U.S. patent application number 12/336467 was filed with the patent office on 2010-06-17 for symmetrical auto transformer wye topologies.
Invention is credited to Jian Huang, Jeffrey J. White.
Application Number | 20100148900 12/336467 |
Document ID | / |
Family ID | 42239780 |
Filed Date | 2010-06-17 |
United States Patent
Application |
20100148900 |
Kind Code |
A1 |
Huang; Jian ; et
al. |
June 17, 2010 |
SYMMETRICAL AUTO TRANSFORMER WYE TOPOLOGIES
Abstract
Various embodiments of multi-phase transformers are disclosed.
For example, a transformer includes primary windings, secondary
windings and third windings. Primary windings, secondary windings
and third windings may include sub windings coupled to form
junctions. Primary windings are coupled at ends to form a delta
configuration. Secondary windings are coupled to primary windings.
Third windings are coupled to primary windings and secondary
windings. Secondary windings and the third windings may be
magnetically coupled to primary windings. The outputs at second
ends of third windings are greater than the outputs at the second
ends of secondary windings. In some embodiments, the outputs at
adjacent second ends of the third windings are substantially equal.
In other embodiments, a phase angle difference of outputs at
adjacent second ends of third windings is substantially equal. In
some embodiments, the phase angle difference of outputs at adjacent
second ends of secondary windings is substantially equal.
Inventors: |
Huang; Jian; (Everett,
WA) ; White; Jeffrey J.; (Shoreline, WA) |
Correspondence
Address: |
DUKE W. YEE
YEE & ASSOCIATES, P.C., P.O. BOX 802333
DALLAS
TX
75380
US
|
Family ID: |
42239780 |
Appl. No.: |
12/336467 |
Filed: |
December 16, 2008 |
Current U.S.
Class: |
336/12 |
Current CPC
Class: |
H01F 30/14 20130101;
H01F 30/02 20130101 |
Class at
Publication: |
336/12 |
International
Class: |
H01F 30/12 20060101
H01F030/12 |
Claims
1. A multi-phase transformer, comprising: a first group of windings
having a plurality of primary windings and each primary winding
having a first end and a second end; wherein the first end of each
of the primary windings is coupled at a common junction to form a
wye configuration; and wherein each of the primary winding is
configured to receive a phase of a multi-phase input voltage at the
second end of each of the primary windings; a second group of
windings having a plurality of secondary windings and each
secondary winding has a first end and a second end; wherein each
secondary winding is magnetically coupled to a primary winding; and
a third group of windings having a plurality of third windings and
each third winding has a first end and a second end; wherein each
third winding is magnetically coupled to a primary winding from
among the plurality of primary windings such that an output voltage
at the second end of the third windings is higher than an output
voltage at the second end of the secondary windings and the second
end of the primary windings.
2. The transformer of claim 1, wherein a phase angle difference of
the output voltage at two adjacent second ends of the third
windings are substantially the same.
3. The transformer of claim 2, wherein the output voltage at the
second end of the third windings are substantially equal and the
output voltage at the second end of the secondary windings and the
second end of the primary windings are substantially equal.
4. The transformer of claim 1, wherein a plurality of second end of
the third windings are configured to couple to a rectifier circuit
to rectify the output voltage at the second end of the third
windings and output a rectified second voltage.
5. The transformer of claim 4, wherein the rectified second voltage
is greater than a rectified output voltage derived from rectifying
the input voltage.
6. The transformer of claim 4, wherein the second end of the
primary windings and the secondary windings are configured to
couple to a rectifier circuit to rectify an output at the second
end of the primary windings and the secondary windings, and output
a rectified first voltage that is less than the rectified second
voltage.
7. The transformer of claim 6, wherein the rectified first voltage
is substantially equal to a rectified output voltage derived from
rectifying the input voltage.
8. The transformer of claim 2, wherein the phase difference is 60
degrees.
9. The transformer of claim 1, wherein the the first end of each of
the secondary winding is coupled to the common junction of the
primary windings; and the first end of each of the third winding is
coupled to a second end of a secondary winding from among the
plurality of secondary windings.
10. The transformer of claim 9, wherein the third windings includes
a first sub-winding with two ends and a second sub-winding with two
ends; wherein the first sub-winding and the second sub-winding is
connected in series at one end; wherein the other end of the first
sub-winding corresponds to the first end of the third winding;
wherein the other end of the second sub-winding corresponds to the
second end of the third winding; and a vector of the induced
voltage in the first sub-winding is different than a second
sub-winding such that a phase angle difference of the output
voltage at two adjacent second ends of the third windings are
substantially the same.
11. The transformer of claim 9, wherein a vector of the induced
voltage in the third windings is such that a phase angle difference
of the output voltage at two adjacent second ends of the third
windings are substantially the same.
12. The transformer of claim 11, wherein a vector of the induced
voltage in the primary windings and the secondary windings is such
that a phase angle of the output voltage at the second end of the
third winding is different than a phase angle of the output at the
second end of the primary winding or the secondary winding to which
the first end of the third winding is coupled to.
13. The transformer of claim 1, wherein all the secondary windings
include a first sub-winding with two ends wherein one end of first
sub-winding corresponds to the first end of the secondary winding;
and a plurality of second sub-windings with two ends; another end
of the first sub-winding and one end of some of the second
sub-windings are coupled together; wherein the other end of each of
the second sub-windings coupled to the first sub-winding is coupled
to one end of at least one other second sub-winding at
sub-junctions, wherein the other ends of the other sub-windings
correspond to a plurality of second ends of the secondary winding;
the first end of each of the third winding is coupled to either a
second end of one of the primary windings or a sub-junction of one
of the secondary windings; and the first end of each of the
secondary winding is coupled to the second end of the third
windings.
14. The transformer of claim 12, wherein a vector of the induced
voltage in the third windings is such that a phase angle difference
of the output voltage at two adjacent second ends of the third
windings are substantially the same.
15. The transformer of claim 12, wherein a vector of the induced
voltage in the secondary windings is such that a phase angle
difference of an output voltage at two adjacent second ends of the
second windings are substantially the same.
15. A multi-phase transformer, comprising: a first group of
windings having a plurality of primary windings and each primary
winding having a first end and a second end; wherein the first end
of each of the primary windings is coupled at a common junction to
form a wye configuration; wherein each of the primary windings
includes one or more sub primary windings coupled in series, and a
junction of two sub primary winding define an interior junction;
and wherein each of the primary windings is configured to receive a
phase of a multi-phase input voltage at the second end of each of
the primary windings; a second group of windings having a plurality
of secondary windings and each secondary winding has a first end
and a second end; wherein each secondary winding is magnetically
coupled to a primary winding; and a third group of windings having
a plurality of third windings and each third winding has a first
end and a second end; wherein each third winding is magnetically
coupled to a primary winding from among the plurality of primary
windings such that an output voltage at the second end of the third
windings is higher than an output voltage at the second end of the
secondary windings and the second end of the primary windings.
16. The transformer of claim 15, wherein a vector of the induced
voltage in the third windings is such that the phase angle
difference of the output voltage at two adjacent second ends of the
third windings are substantially the same.
17. The transformer of claim 15, wherein a vector of the induced
voltage in the secondary windings is such that the phase angle
difference of the output voltage at two adjacent second ends of the
second windings are substantially the same.
18. The transformer of claim 15, wherein the first end of each of
the secondary winding is coupled to either the common junction of
the primary windings or to the sub junction of one of the primary
windings; and wherein the first end of each of the third winding is
coupled to the second end of one of the primary windings, second
end of one of the secondary winding or the sub junction of one of
the primary winding.
19. The transformer of claim 18, wherein a vector of the induced
voltage in the third windings is such that the phase angle
difference of the output voltage at two adjacent second ends of the
third windings are substantially the same.
20. The transformer of claim 15, wherein some of the third windings
include a first sub-winding with two ends and a second sub-winding
with two ends; wherein the first sub-winding and the second
sub-winding is connected in series at one end and form a
sub-junction; wherein the other end of the first sub-winding
corresponds to the first end of the third winding; and wherein the
other end of the second sub-winding corresponds to the second end
of the third winding; wherein the first end of each of the
secondary winding is coupled to either the sub junction of one of
the primary windings or the sub-junction of one of the third
windings; and wherein the first end of each of the third winding is
coupled to either the second end of one of the primary windings or
the sub junction of one of the primary windings.
21. The transformer of claim 20, wherein a vector of the induced
voltage in the third windings is such that the phase angle
difference of the output voltage at two adjacent second ends of the
third windings are substantially the same.
22. The transformer of claim 20, wherein a vector of the induced
voltage in the secondary windings is such that the phase angle
difference of the output voltage at two adjacent second ends of the
second windings are substantially the same.
23. The transformer of claim 15, wherein some of the secondary
windings include a first sub-winding with two ends and a second
sub-winding with two ends; wherein the first sub-winding and the
second sub-winding are connected in series at one end to form a
sub-junction; wherein the other end of the first sub-winding
corresponds to the first end of the secondary winding; and wherein
the other end of the second sub-winding corresponds to the second
end of the secondary winding; wherein the first end of each of the
secondary winding is coupled either to the sub junction of one of
the primary windings or to the common junction; and wherein the
first end of each of the third winding is coupled to either the
second end of one of the primary windings or to the sub junction of
one of the secondary windings.
24. The transformer of claim 23, wherein a vector of the induced
voltage in the third windings is such that the phase angle
difference of the output voltage at two adjacent second ends of the
third windings are substantially the same.
25. The transformer of claim 23, wherein a vector of the induced
voltage in the secondary windings is such that the phase angle
difference of the output voltage at two adjacent second ends of the
second windings are substantially the same.
26. The transformer of claim 15, wherein all of the secondary
windings include a first sub-winding with two ends and a second
sub-winding with two ends; wherein the first sub-winding and the
second sub-winding are connected in series at one end to form a
sub-junction; wherein the other end of the first sub-winding
corresponds to the first end of the secondary winding; and wherein
the other end of the second sub-winding corresponds to the second
end of the secondary winding; wherein the first end of each of the
secondary winding is coupled to the sub junction of one of the
primary windings; and wherein the first end of each of the third
winding is coupled either to the second end of one of the primary
windings or to the sub_junction of one of the secondary
windings.
27. The transformer of claim 26, wherein a vector of the induced
voltage in the third windings is such that the phase angle
difference of the output voltage at two adjacent second ends of the
third windings are substantially the same.
28. The transformer of claim 26, wherein a vector of the induced
voltage in the secondary windings is such that the phase angle
difference of the output voltage at two adjacent second ends of the
second windings are substantially the same.
29. The transformer of claim 15, wherein all of the secondary
windings include a first sub-winding with two ends wherein one end
corresponds to the first end of the secondary winding and a
plurality of second sub-windings with two ends; wherein the other
end of the first sub-winding is coupled to one end of the second
sub-winding; wherein the other end of the second sub-winding is
coupled to one end of another second sub-winding to form a
sub-junction; and wherein the other end of the another second
sub-winding corresponds to the second end of the secondary winding;
wherein the first end of each of the secondary winding is coupled
to the second end of one of the primary windings; and wherein the
first end of each of the third winding is coupled either to the
second end of one of the primary windings or to the sub junction of
one of the secondary windings.
30. The transformer of claim 29, wherein a vector of the induced
voltage in the third windings is such that the phase angle
difference of the output voltage at two adjacent second ends of the
third windings are substantially the same.
31. The transformer of claim 29, wherein a vector of the induced
voltage in the secondary windings is such that the phase angle
difference of the output voltage at two adjacent second ends of the
second windings are substantially the same.
32. The transformer of claim 15, wherein each of the secondary
winding has a plurality of second ends; wherein all of the
secondary windings include a first sub-winding with two ends
wherein one end corresponds to the first end of the secondary
winding and a plurality of second sub-winding with two ends;
wherein the other end of the first sub-winding and one end of all
of the second sub-windings are connected together; and wherein the
other ends of the second sub-windings corresponds to the plurality
of second ends of the secondary winding; wherein the first end of
each of the secondary winding is coupled to the common junction of
the primary windings; and wherein the first end of each of the
third winding is coupled either to the second end of one of the
primary windings or to one of the second ends of one of the
secondary windings.
33. The transformer of claim 32, wherein a vector of the induced
voltage in the third windings is such that the phase angle
difference of the output voltage at two adjacent second ends of the
third windings are substantially the same.
34. The transformer of claim 32, wherein s vector of the induced
voltage in the secondary windings is such that the phase angle
difference of the output voltage at two adjacent second ends of the
second windings are substantially the same.
35. The transformer of claim 15, wherein each of the secondary
winding has a plurality of second ends; all of the secondary
windings include a first sub-winding with two ends wherein one end
corresponds to the first end of the secondary winding and a
plurality of second sub-windings with two ends; wherein the other
end of the first sub-winding and one end of some of the second
sub-windings are coupled together; wherein the other ends of each
of the second sub-windings that are coupled to the first
sub-winding are each coupled to one end of at least one additional
second sub-winding to form a sub-junctions; and wherein the other
ends of the additional sub-windings correspond to the plurality of
second ends of the secondary winding; wherein the first end of each
of the secondary winding is coupled to the interior junction of one
of the primary windings; and wherein the first end of each of the
third winding is coupled either to the second end of one of the
primary windings or to the sub-junction of one of the secondary
windings.
36. The transformer of claim 35, wherein a vector of the induced
voltage in the third windings is such that the phase angle
difference of the output voltage at two adjacent second ends of the
third windings are substantially the same.
37. The transformer of claim 35, wherein a vector of the induced
voltage in the secondary windings is such that the phase angle
difference of an output voltage at two adjacent second ends of the
second windings are substantially the same.
38. The transformer of claim 15, wherein some of the third windings
include a plurality of second ends; wherein some of the third
windings include a first sub-winding with two ends wherein one end
corresponds to the first end of the third winding and a plurality
of second sub-windings with two ends; wherein the other end of the
first sub-winding and one end of the plurality of second
sub-windings are coupled together; and wherein the other ends of
each of the second sub-windings correspond to the plurality of
second ends of the third windings; wherein the first end of each of
the secondary winding is coupled to the interior junction of one of
the primary windings; wherein the first end of each of the third
winding without the plurality of second ends is coupled to the
second end of one of the primary windings; and wherein the first
end of each of the third winding with the plurality of second ends
is coupled to the second ends of the third windings without the
plurality of second ends.
39. The transformer of claim 38, wherein a vector of the induced
voltage in the third windings is such that the phase angle
difference of the output voltage at two adjacent second ends of the
third windings are substantially the same.
40. The transformer of claim 38, wherein a vector of the induced
voltage in the secondary windings is such that the phase angle
difference of an output voltage at two adjacent second ends of the
second windings are substantially the same.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is related to U.S. patent application,
entitled "SYMMETRICAL AUTO TRANSFORMER DELTA TOPOLOGIES", Docket
No. 08-0528, Ser. No. ______ , filed on even date herewith, the
disclosure of which is Incorporated herein by reference in its
entirety.
BACKGROUND
[0002] 1. Field of the Disclosure
[0003] This disclosure is directed to transformers.
[0004] 2. Related Art
[0005] In many applications, for example, shipboard and aircraft
applications, a high voltage direct current (DC) power is used to
power motor controllers. Typically, a three phase alternating
current (AC) voltage of 230 Volts (root mean square (rms)) is
generated in a ship or an aircraft and the generated AC voltage is
applied to an auto transformer rectifier unit (ATRU). The ATRU
generates a DC voltage of .+-.270 Volts. The DC voltage from the
ATRU is used to power motor controllers.
[0006] The voltage output of the motor controllers is limited by
the rectified DC voltage of the ATRU. It is desirable to increase
the voltage output of the motor controllers.
[0007] In order to increase the voltage output of the motor
controllers, various approaches have been tried. One approach is to
generate a higher input AC voltage from the generator. This
approach has shortcomings because by increasing the generator
output AC voltage, the insulation level of the ship or aircraft has
to be increased. Furthermore, increased input AC voltage leads to
additional challenges like corona, high voltage spikes and
component breakdown.
[0008] Another approach has been to acid a step-up (or step up)
autotransformer before the motor controller to get a higher
rectified, output DC voltage or after the motor controller to get a
higher output AC voltage. Adding an additional step-up transformer
before or after the motor controller adds additional heavy
components to the overall power generation system. This increases
overall weight of the system and is undesirable in environments
that may be sensitive to weight, for example, ships and
aircrafts.
[0009] Continuous efforts are being made to deal with the foregoing
issues.
SUMMARY OF THE DISCLOSURE
[0010] In one embodiment, a multi-phase transformer is disclosed.
The multi-phase transformer includes a first group of windings, a
second group of windings and a third group of windings. The first
group of windings includes a plurality of primary windings with a
first end and a second end. The first end of each of the primary
windings is coupled at a common junction to form a wye
configuration. Each of the primary windings are configured to
receive one phase of a multi-phase input voltage at the second ends
of the primary windings.
[0011] The second group of windings include a plurality of
secondary windings with each secondary winding having a first end
and a second end. Each secondary winding may be magnetically
coupled to a primary winding.
[0012] The third group of windings includes a plurality of third
windings. Each third winding includes a first end and a second end.
Each third winding may be magnetically coupled to a primary winding
such than an output voltage at the second end of the third windings
is higher than an output voltage at the second end of the secondary
windings and the second end of the primary windings.
[0013] In another embodiment, another multi-phase transformer is
disclosed. The multi-phase transformer includes a first group of
windings, second group of windings and third group of windings. The
first group of windings includes a plurality of primary windings,
with each primary winding having a first end and a second end. Each
primary winding includes one or more sub primary windings that may
be coupled in series with a junction of two sub primary windings
defining an interior junction. The first end of each of the primary
windings is coupled at a common junction to form a wye
configuration. Each primary winding is configured to receive one
phase of a multi-phase input voltage at the second end.
[0014] The second group of windings includes a plurality of
secondary windings with each secondary winding having a first end
and a second end. Each secondary winding may be magnetically
coupled to a primary winding.
[0015] The third group of windings includes a plurality of third
windings with each third winding having a first end and a second
end. Each third winding may be magnetically coupled to a primary
winding. The third group of windings is configured with respect to
the first group of windings and the second group of windings such
that an output voltage at the second end of the third windings is
higher than an output voltage at the second end of the secondary
windings and the primary windings.
[0016] In some embodiments, some of the secondary windings include
a plurality of sub-windings. In other embodiments, some of the
third windings include a plurality of sub-windings.
[0017] This brief summary has been provided so that the nature of
the disclosure may be understood quickly. A more complete
understanding of the disclosure may be obtained by reference to the
following detailed description of embodiments, thereof in
connection with the attached drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] The foregoing features and other features of the present
disclosure will now be described with respect to the drawings. In
the drawings, the same components have the same reference numerals.
The illustrated embodiment is intended to illustrate, but not to
limit the disclosure. The drawings include the following
figures:
[0019] FIG. 1A is a winding diagram of a multi-phase
auto-transformer.
[0020] FIG. 1B is a phasor diagram for the multi-phase
auto-transformer of FIG. 1A.
[0021] FIG. 2 is an example of an auto-transformer rectifier unit
for use with multi-phase auto transformers.
[0022] FIG. 3A is a winding diagram for an alternate multi-phase
auto-transformer.
[0023] FIG. 3B is a phasor diagram for the multi-phase
auto-transformer of FIG. 3A.
[0024] FIG. 4A is a winding diagram for an alternate multi-phase
auto-transformer.
[0025] FIG. 4B is a phasor diagram for the multi-phase
auto-transformer of FIG. 4A.
[0026] FIG. 5A is a winding diagram for an alternate multi-phase
auto-transformer.
[0027] FIG. 5B is a phasor diagram for the multi-phase
auto-transformer of FIG. 5A.
[0028] FIG. 6A is a winding diagram for an alternate multi-phase
auto-transformer.
[0029] FIG. 6B is a phasor diagram for the multi-phase
auto-transformer of FIG. 6A.
[0030] FIG. 7A is a winding diagram for an alternate multi-phase
auto-transformer.
[0031] FIG. 7B is a phasor diagram for the multi-phase
auto-transformer of FIG. 7A.
[0032] FIG. 8A is a winding diagram for an alternate multi-phase
auto-transformer.
[0033] FIG. 8B is a phasor diagram for the multi-phase
auto-transformer of FIG. 8A.
[0034] FIG. 9A is a winding diagram for an alternate multi-phase
auto-transformer.
[0035] FIG. 9B is a phasor diagram for the multi-phase
auto-transformer of FIG. 9A.
[0036] FIG. 10A is a winding diagram for an alternate multi-phase
auto-transformer.
[0037] FIG. 10B is a phasor diagram for the multi-phase
auto-transformer of FIG. 10A.
[0038] FIG. 11A is a winding diagram for an alternate multi-phase
auto-transformer.
[0039] FIG. 11B is a phasor diagram for the multi-phase
auto-transformer of FIG. 11A.
[0040] FIG. 12A is a winding diagram for an alternate multi-phase
auto-transformer.
[0041] FIG. 12B is a phasor diagram for the multi-phase
auto-transformer of FIG. 12A.
[0042] FIG. 13A is a winding diagram for an alternate multi-phase
auto-transformer.
[0043] FIG. 13B is a phasor diagram for the multi-phase
auto-transformer of FIG. 13A.
[0044] FIG. 14A is a winding diagram for an alternate multi-phase
auto-transformer.
[0045] FIG. 14B is a phasor diagram for the multi-phase
auto-transformer of FIG. 14A.
[0046] FIG. 15A is a winding diagram for an alternate multi-phase
auto-transformer.
[0047] FIG. 15B is a phasor diagram for the multi-phase
auto-transformer of FIG. 15A.
DETAILED DESCRIPTION
[0048] Definitions:
[0049] The following definitions are provided for convenience, as
they are used in describing various embodiments of this
disclosure.
[0050] "First group of windings" means a collection of a plurality
of primary windings.
[0051] "Second group of windings" means a collection of a plurality
of secondary windings.
[0052] "Third group of windings" means a collection of a plurality
of third windings.
[0053] "Primary winding" is a winding that may have a winding or a
plurality of sub windings. Primary windings have two ends. Primary
windings may have one or more sub primary windings coupled
together. In some embodiments, the sub windings of a primary
winding may be coupled in series at one end to form a
sub-junction.
[0054] "Interior junction" means a junction of two sub primary
windings of a primary winding.
[0055] "Common junction" means a junction of two or more primary
windings coupled together at one of their ends. Three primary
windings may be coupled at one of their ends to form a WYE winding
configuration.
[0056] "Secondary winding" is a winding that may have a winding or
a plurality of sub-windings. Secondary windings have at least a
first end and a second end. In some embodiments, the sub-windings
may be coupled together to form a sub-junction. Secondary windings
may be magnetically coupled to a primary winding. Sub-windings of
secondary winding may be magnetically coupled to the same primary
winding or a different primary winding.
[0057] "Sub-junction" means a junction created by a plurality of
sub-windings. In some embodiments, two sub-windings may be coupled
in series. In other embodiments, three sub-windings may be coupled
at one end to form a WYE configuration.
[0058] "Third winding" means a winding that may have a winding or a
plurality of sub-windings. A third winding may have at least a
first end and a second end. A third winding may be magnetically
coupled to a primary winding. Sub-windings of a third winding may
be magnetically coupled to the same primary winding or a different
primary winding.
[0059] To facilitate an understanding of the preferred embodiment,
the general architecture of an auto-transformer rectifier system
with an exemplary auto-transformer will be described. The specific
architecture of various alternate embodiments of auto-transformers
will then be described with respect to the general
architecture.
[0060] A multi-phase transformer 100 is described with respect to
FIGS. 1A and 1B. FIG. 1A is a winding diagram for multi-phase
transformer 100. FIG. 1B is a phasor diagram for multi-phase
transformer 100. Transformer 100 is an example of a six phase or
twelve pulse multi-phase transformer.
[0061] Referring to FIG. 1A, the transformer 100 may include a
first group of windings 102, a second group of windings 104 and a
third group of windings 106. The first group of windings 102 may
include a plurality of primary windings 108A-108C.
[0062] One end of the primary windings is coupled together at a
common junction CJ to form a WYE configuration. The second end of
each primary winding is configured to receive one phase of a
multi-phase input voltage. For example primary winding 108A
receives one phase of a multi-phase input voltage at second end
114A. Similarly, primary winding 108B receives another phase of a
multi-phase input voltage at second junction 114B. Primary winding
108C receives yet another phase of a multi-phase input voltage at
second junction 1140.
[0063] The second group of windings 104 may include a plurality of
secondary windings, for example, secondary windings 116A1-116C1.
Each secondary winding 116A1-116C1 includes a first end 118 and a
second end 120. Each secondary winding 116A1-116C1 may be
magnetically coupled to one of the primary windings 108A-108C.
[0064] The third group of windings 106 may include a plurality of
third windings. For example, third windings 122A1, 122A2, 122B1,
122B2, 122C1 and 122C2. Each third winding 122A1-122C2 may include
a first end 124 and a second end 126. Each third winding
122A1-122C2 may be magnetically coupled to one of the primary
windings 108A-108C.
[0065] In one embodiment, the first end 118 of each secondary
winding 116A1-116C1 may be coupled to the common junction CJ.
[0066] In one embodiment, the first end 124 of each third winding
122A1-122C2 may be coupled either to a secondary winding
116A1-116C2 or to a primary winding 108A-108C. The third group of
windings 106 may be configured with respect to the first group of
windings 102 and the second group of windings 104 such that an
output voltage Vout2 at the second end 126 of the third windings
122A1-122C2 is higher than an output voltage Vout1 at the second
end 120 of the secondary windings 116A1-116C2 and the second end
114A-114C of the primary windings 108A-108C.
[0067] In one embodiment, a phase angle difference of the output
voltage Vout2 at two adjacent second ends of third windings is
substantially the same. For example, the phase angle difference of
the output voltage Vout2 at second end 126 of two adjacent third
windings 122A1-122A2, 122A2-122B1, 122B1-122B2, 122B2-122C1,
122C1-122C2 and 122C2-122A1 is substantially the same.
[0068] In one embodiment, the output voltage Vout2 at the second
end of the third windings is substantially equal. For example, the
output voltage Vout2 at the second end 126 of the third windings
122A1-122C2 is substantially the same.
[0069] In one embodiment, the output voltage Vout1 at the second
end of secondary windings 116 and at the second end of the primary
windings 108 is substantially equal. For example, the output
voltage Vout1 at the second end 120 of secondary windings
116A1-116C2 and at the second end 114A-114C of primary windings
108A-108C is substantially equal.
[0070] In one embodiment, the output voltage Vout2 is greater than
output voltage Vout1.
[0071] FIG. 1A also shows an example of the number of turns for
various windings and sub windings. Some of the windings having
substantially the same number of turns. For example, the primary
windings 108A, 108B and 108C may have substantially the same number
of turns N1. Similarly, the secondary windings 116A1, 116B1 and
116C1 may have substantially the same number of turns N1. Further,
the third windings 122A1-122C2 may have substantially the same
number of turns N2.
[0072] Now referring to FIG. 1B, an example of a phasor diagram 130
for the multi-phase transformer 100 of FIG. 1A is disclosed. As one
skilled in the art appreciates, the phasor diagram, graphically
depicts various aspects of the multi-phase transformer. For
example, the phasor diagram depicts the relationship between the
first group of windings, second group of windings and the third
group of windings. More specifically, various windings are
represented by lines in a phasor diagram and the length of a line
represents one number of turns of the winding. The lines in a
phasor diagrams are vector lines depicting a vector of the induced
voltage. Two vector lines that are parallel to each other represent
magnetic coupling between corresponding two windings. The radial
length of each segment between two junctions along the
circumference represents the phase angle difference between the
output signals at those junctions, with the full circle
representing 360 degrees. The common center of the circle
represents the effective electrical neutral position.
[0073] The phasor diagram 130 may include a first circle 132 and a
second circle 134, both having a common center S. In one
embodiment, the common center S corresponds to the common junction
CJ of transformer 100. The sides SA, SB and SC represent the
primary windings 108A-108C, respectively.
[0074] Points A1V1, B1V1 and C1V1 represent the second end 120 the
secondary windings 116A1, 116B1 and 116C1 respectively. Similarly,
points A1V2, B1V2 and C1V2 represent second end 126 of third
windings 122A1, 122B1 and 122C1 respectively.
[0075] For example, lines S-A1V1, S-B1V1 and S-C1V1 represent the
secondary windings 116A1, 116B1 and 116C1 respectively. Lines
A-AV2, A1V1-A1V2, B-BV2, B1V1-B1V2, C-CV2 and C1V1-C1V2 represent
the third windings 122A1, 122A2, 122B1, 122B2, 122C1 and 122C2
respectively.
[0076] The length of the lines S-A, S-B and S-C represent the
number of turns N1 for the primary windings 108A, 108B and 103C.
Length of the lines S-A1V1, S-B1V1 and S-C1V1 represent the number
of turns N1 for the secondary windings 116A1, 116B1 and 116C1,
respectively. The length of the lines A-AV2, A1V1-A1V2, B-BV2,
B1V1-B1V2, C-CV2 and C1V1-C1V2 represent the number of turns N2 for
the third windings 122A1-122C2, respectively.
[0077] In summary, points A, B and C in the phasor diagram
represent the second end 114A-114C of the primary windings, points
A1V1, B1V1 and C1V1 represent the second end 120 of the secondary
windings 116A1-116C1 and points AV2, A1V2, BV2, B1V2, CV2 and C1V2
represent the second end 126 of the third windings 122A1-122C1
respectively.
[0078] The lines SA, SB and SC represent an input AC voltage Vin
applied to the second ends A, B and C of the primary windings. As
it is evident from the phasor diagram, a three phase input voltage
Vin depicted as phaseA_230, phaseB_230 and phaseC_230 is applied,
with each phase separated by about 120 degrees.
[0079] As previously described, the lines in a phasor diagrams are
vector lines depicting a vector of the induced voltage. For
example, the vector of the induced voltage in primary windings SA,
SB and SC are depicted by the arrows 136, 138 and 140. Similarly,
the arrows on lines representing the secondary windings and the
third windings represent the vector of the induced voltage. For
example, arrows 142 and 144 represent the vector of the induced
voltage in secondary winding 116A1 and 116B1 respectively. The
arrows 146 and 148 represent the vector of the induced voltage in
the third windings 122A1 and 122A2, respectively.
[0080] In one embodiment, a vector of the induced voltage in the
secondary windings is such that they are about 180 degrees out of
phase with the vector of the induced voltage in a primary winding
to which they may be magnetically coupled. In one embodiment, a
vector of the induced voltage in the primary windings and the
secondary windings is such that the phase angle difference of the
output voltage at two adjacent second ends of the primary windings
and the secondary windings is substantially the same.
[0081] In one embodiment, a vector of the induced voltage in the
third windings is such that they are in phase or about 180 degrees
out of phase with the vector of the induced voltage in a primary
winding to which they may be magnetically coupled. In one
embodiment, the vector of the induced voltage in the third windings
is such that the phase angle difference of the output voltage at
two adjacent second ends of the third windings is substantially the
same.
[0082] The phasor diagram 130 shows an example of a vector of the
induced voltage in the primary windings, secondary windings and the
third windings.
[0083] For example, in one embodiment, the vector of the induced
voltage in each of the secondary windings is about 180 degrees out
of phase with the vector of the induced voltage in the primary
winding. For example, the vector of the induced voltage in the
secondary winding 116A1 depicted by line S-A1V1 is about 180
degrees out of phase with the vector of the induced voltage in the
primary winding 108C depicted by line SC.
[0084] In one embodiment, a vector of the induced voltage in a
third winding coupled to a secondary winding is in phase with the
vector of the corresponding secondary winding. Further, the vector
of the induced voltage in a third winding coupled to a primary
winding is in phase with the vector of the induced voltage of that
primary winding. For example, the vector of the induced voltage in
the third winding 122A1 depicted by line A-AV2 and coupled to
primary winding 108A depicted by line S-A is in phase with the
vector of the induced voltage in the primary winding 108A.
[0085] FIG. 2 shows an example of a auto-transformer rectifier
system 200. The auto-transformer rectifier system 200 may include
an auto-transformer 202, a first multi-pulse rectifier 204 and a
second multi-pulse rectifier 206. The auto-transformer 202 may be
similar to the auto-transformer described with respect to FIGS. 1A
and 1B.
[0086] The first multi-phase rectifier 204 may include a first
input block 208 and a first output block 210. The first input block
208 may be configured to couple to the second end of secondary
windings to receive the first output voltage VoutF1 from the
auto-transformer 202. The first multi-phase rectifier 204 rectifies
the first output voltage VOUTF1 and provides a rectified first
output voltage VROUTF1. The first output voltage VOUTF1 may be the
same as the output voltage Vout1 of the auto-transformer, as
described above with respect to FIGS. 1A and 1B.
[0087] The second multi-phase rectifier 206 may include a second
input block 212 and a second output block 212. The second input
block 212 is configured to couple to the second end of third
windings to receive a second output voltage VOUTF2 from the
auto-transformer. The second multi-phase rectifier 206 rectifies
the second output voltage VOUTF2 and provides a rectified second
output voltage VROUTF2. The second output voltage VOUTF2 may be the
same as the output voltage Vout2 of the auto-transformer described
above with respect to FIGS. 1A and 1B.
[0088] The first output voltage VOUTF1 may be the same as the
output voltage Vout1 of the auto-transformer described above with
respect to FIGS. 1A and 1B. The second output voltage VOUTF2 may be
the same as the output voltage Vout2 of the auto-transformer
described above with respect to FIGS. 1A and 1B. As previously
described, the auto-transformer 100 of FIG. 1A and 1B in one
embodiment, provides a six phase output Vout1 at the second end of
the secondary windings and a six phase output voltage Vout2 at the
second end of third windings.
[0089] In an exemplary system, an input AC voltage of 230 Volts is
applied to the auto-transformer. This may generate a 230 Volts,
RMS, AC voltage at the output of the second end of secondary
windings, with six phases, with each phase having a positive pulse
and a negative pulse. The input AC voltage of 230 Volts may also
generate a 307 Volts, RMS, AC voltage at the output of the second
end of third windings.
[0090] The six 230 Volts, positive pulses are applied to the first
input block 208 and rectified by the first multi-phase rectifier
204 to provide +270 Volts DC at the first output block 210. The six
negative 230 Volts, pulses are also applied to the first input
block 208 and rectified by the first multi-phase rectifier 204 to
provide -270 Volts DC at the first output block 210.
[0091] The six 307 Volts, positive pulses are applied to the second
input block 212 and rectified by the second multi-phase rectifier
206 to provide +360 Volts DC at the second output block 214. The
six negative 307 Volts pulses are applied to the second input block
212 and rectified by the second multi-phase rectifier 206 to
provide -360 Volts DC at the second output block 214.
[0092] Although the embodiment has been described with respect to a
six phase (12-pulse) auto-transformer and a 12-pulse rectifier, the
disclosure is not limited to this specific example and may be
modified suitably to construct auto-transformer rectifier systems
to support auto-transformers with different number of output
phases. For example, the auto-transformer rectifier system may be
adapted for use with various embodiments of multi-phase
transformers described in this disclosure.
[0093] Another embodiment of a multi-phase transformer 300 is
described with respect to FIGS. 3A and 3B. Transformer 300 is an
example of a six phase or twelve pulse multi-phase transformer. The
multi-phase transformer 300 described with respect to FIGS. 3A and
3B is substantially similar to the multi-phase transformer 100
described with respect to FIGS. 1A and 1B except that the third
group of windings 106 may include a plurality of third windings
122A1-122C2, with each third winding 122A1-122C2 including at least
two sub-windings connected in series. Similarities and differences
between auto-transformer 100 and auto-transformer 300 will be now
described in more detail below.
[0094] FIG. 3A is a winding diagram for a multi-phase transformer
300. The transformer 300 may include a first group of windings 102,
a second group of windings 104 and a third group of windings 106.
The first group of windings 102 and the second group of windings
104 of auto-transformer 200 are constructed and coupled similar to
the auto-transformer 100 described above with respect to FIGS. 1A
and 1B, with the same reference numerals describing the same
elements.
[0095] The third group of windings 106 may include a plurality of
third windings 122A1-122C2, with the ends of the third windings
122A1-122C2 defining a first end 124 and a second end 126. Each of
the third winding 122A1-122C2 may include at least two sub-windings
connected in series. For example, third winding 122A1 may include a
first sub-winding 122A11 and second sub-winding 122A12 connected in
series at one end. The other end of first sub-winding 122A11
corresponds to the first end 124 of the third winding 122A1 and the
other end of second sub-winding 122A12 corresponds to the second
end 126 of the third winding 122A1.
[0096] Each of the third winding 122A1-122C2 may be magnetically
coupled to a primary winding 108A-108C. For example, the first
sub-winding 122A11 may be magnetically coupled to a primary winding
108A-108C and the second sub-winding 122A12 may be magnetically
coupled to a primary winding 108A-108C. The second sub-winding
122A12 may be magnetically coupled to a primary winding 108A-108C
different than the primary winding that the first sub-winding
122A11 may be magnetically coupled to.
[0097] The first end 124 of each of the third winding 122A1-122C2
may be coupled to a secondary winding 116A-116C or to a primary
winding 108A-108C with the third group of windings 106 configured
with respect to the first group of windings 102 and the second
group of windings 104 such that the output voltage Vout2 at the
second end 126 of the third windings 122A1-122C2 is higher than the
output voltage Vout1 at the second end 120 of the secondary
windings 116A1-116C1 and the second end 114A-114C of the primary
windings 108A-108C, respectively.
[0098] In one embodiment, the first end 118 of the secondary
winding 116A1-116C1 may be coupled to the common junction CJ of the
primary windings 108A-108C.
[0099] In another embodiment, the first end 124 of some of the
third windings 122A1-122C2 may be coupled to the second end 120 of
the secondary winding 116A1-116C1. For example, the first end 124
of the third winding 122A2 may be coupled to the second end 120 of
secondary winding 116A1.
[0100] In one embodiment, the phase angle difference of the output
voltage Vout2 at two adjacent second ends 126 of third windings
122A1-122C2 is substantially the same.
[0101] In one embodiment, the output voltage Vout2 at the second
end 126 of the third windings 122A1-122C2 is substantially equal
and the output voltage Vout1 at the second end 120 of secondary
windings 116A1-116C1 and at the second end 114A-114C of the primary
windings 108A-108C is substantially equal.
[0102] In another embodiment, the output voltage Vout2 is greater
than output voltage Vout1.
[0103] FIG. 3A also shows an example of the number of turns for
various windings and sub windings, with some of the windings or sub
windings having substantially the same number of turns. For
example, the primary windings 108A, 108B and 1081 may have
substantially the same number of turns N1. Similarly, the secondary
windings 116A1, 116B1 and 116C1 may have substantially the same
number of turns N1. For example, the first sub-windings 122A11 and
first sub-winding 122B11 of third windings 122A1 and 122B1 may have
substantially the same number of turns N2.
[0104] Now referring to FIG. 3B, an example of a phasor diagram 330
for the multi-phase transformer 300 of FIG. 3A is provided. The
phasor diagram 330 may include a first circle 332 and a second
circle 334, both having a common center S that corresponds to the
common junction CJ of transformer 300. The lines SA, SB and SC
represent the primary windings 108A-108C, respectively.
[0105] The phasor diagram details within the first circle 332 is
similar to the phasor diagram 130 described with respect to FIG.
1B. Some of the differences between phasor diagram 330 and phasor
diagram 130 as it relates to the third windings will be discussed
now.
[0106] The line A-A' represents the first sub-winding 122A11 of
third winding 122A1. Similarly, the line A'-AV2 represents the
second sub-winding 122A12 of third winding 122A1. The arrow 148'
represents the vector of the induced voltage in the first
sub-winding 122A11 and the arrow 148'' represents the vector of the
induced voltage in the second sub-winding 122A12. Other third
windings 122A2-122C2 are similarly represented in the phasor
diagram 330.
[0107] The lines SA, SB and SC represent the input AC voltage Vin
that is applied to the second ends A, B and C of the primary
windings. As it is evident from the phasor diagram, a three phase
input voltage Vin depicted as phaseA_230, phaseB_230 and phaseC_230
may be applied, with each phase separated by 120 degrees.
[0108] As previously described, the lines in a phasor diagrams are
vector lines depicting a vector of the induced voltage. For
example, the vectors of the induced voltage in primary windings SA,
SB and SC are depicted by the arrows 136, 138 and 140.
[0109] In one embodiment, a vector of the induced voltage in the
primary windings and the secondary windings may be similar to the
vector of the induced voltage described with respect to transformer
100.
[0110] In one embodiment, a vector of the induced voltage in the
third windings and sub-windings of third windings is such that they
are either in phase or 180 degrees out of phase with the vector of
the induced voltage in a primary winding to which they may be
magnetically coupled.
[0111] In another embodiment, a vector of the induced voltage in
the third windings and sub-windings of sub-windings is such that
the phase angle difference of the output voltage at two adjacent
second ends of the third windings is substantially the same.
[0112] In one embodiment, a vector of the induced voltage in the
primary windings and the secondary windings is such that the phase
angle difference of the output voltage at two adjacent second ends
of the primary windings and the secondary windings is substantially
the same.
[0113] The phasor diagram 330 shows an example of a vector of the
induced voltage in the primary windings, secondary windings and the
third windings.
[0114] In one embodiment, a vector of the induced voltage in a
sub-winding of a third winding is different than the vector of the
induced voltage in another sub-winding of the third winding. For
example, the vector of the induced voltage in sub-winding 122A11 is
different than the vector of the induced voltage in sub-winding
122A12 of third winding 122A1.
[0115] In one embodiment, for the third winding coupled to a
secondary winding (for example, third winding 122A2), the vector of
the induced voltage in the first sub-winding (122A21) is in phase
with the vector of the induced voltage in one of the primary
winding adjacent the secondary winding (primary winding 108A) and
the vector of the induced voltage in the second sub-winding
(122A22) is in phase with the vector of the induced voltage in one
of the other primary winding adjacent the secondary winding
(primary winding 108B).
[0116] In one embodiment, for the third winding coupled to an
external junction of a primary winding (example, third winding
122A1 coupled to primary winding 108A), the vector of the induced
voltage in the first sub-winding (122A11) is about 180 degrees out
of phase with the vector of the induced voltage in one of the
primary windings, other than the primary winding to which the third
winding may be coupled (primary winding 108B). The vector of the
induced voltage in the second sub-winding (122A12) is about 180
degrees out of phase with the vector of the induced voltage in one
of the other primary windings, other than the primary winding to
which the third winding may be coupled (primary winding 108C).
[0117] In another embodiment, a multi-phase transformer 400 is
described with respect to FIGS. 4A and 4B. Transformer 400 is
another example of a six-phase or twelve-pulse multi-phase
transformer. The multi-phase transformer 400 described with respect
to FIGS. 4A and 4B is similar to the multi-phase transformer 100
described above with respect to FIGS. 1A and 1B in that all have a
primary group of windings 102, secondary group of windings 104 and
third group of windings 106.
[0118] One difference between transformer 400 and transformer 100
is that in transformer 400 some of the third windings of the third
group of windings may be magnetically coupled to a different
primary winding than as shown with respect to transformer 100.
Similarity in the construction of transformer 400 and transformer
100 may be understood by referring to FIGS. 4A and 4B and the
description of transformer 100 provided above. The description of
transformer 400 is limited to a description of third windings and
the magnetic coupling of the third windings.
[0119] Referring to FIG. 4A, the third group of windings 106 may
include a plurality of third windings 122A1, 122A2, 122B1, 122B2,
122C1 and 122C2. Each third winding 122A1-122C2 has a first end 124
and a second end 126. Each third winding 122A1-122C2 may be
magnetically coupled to one of the primary windings 108A-108C.
[0120] The first end 124 of each of the third winding 122A1-122C2
may be coupled to a primary winding 108A-108C. The third group of
windings 106 may be configured with respect to the first group of
windings 102 and the second group of windings 104 such that the
output voltage Vout2 at the second end 126 of the third windings
122A1-122C2 is higher than the output voltage Vout1 at the second
end 120 of the secondary windings 116A-116C and the second end
114A-114C of the primary windings 108A-108C.
[0121] In one embodiment, a phase angle difference of the output
voltage Vout2 at two adjacent second ends of the third windings is
substantially the same. For example, the phase angle difference of
the output voltage Vout2 at second end 126 of two adjacent third
windings 122A1-122A2, 122A2-122B1, 122B1-122B2, 122B2-122C1,
122C1-122C2 and 122C2-122A1 is substantially the same.
[0122] In one embodiment, the output voltage Vout2 at the second
end of the third windings is substantially equal. For example, the
output voltage Vout2 at the second end 126 of the third windings
122A1-122C2 is substantially the same.
[0123] In one embodiment, the output voltage Vout1 at the second
end of secondary windings 116A1-116C1 and at the second end of the
primary windings 108A-108C is substantially equal. For example, the
output voltage Vout1 at the second end 120 of secondary windings
116A1-116C1 and at the second end 114A-114C of primary windings
108A-108C is substantially equal.
[0124] In one embodiment, the output voltage Vout2 is greater than
the output voltage Vout1.
[0125] FIG. 4A also shows an example of a number of turns for
various windings and sub windings, with some of the windings having
substantially the same number of turns. For example, the third
windings 122A1 and 122A2 may have substantially the same number of
turns N2.
[0126] Now referring to FIG. 4B, an example of a phasor diagram 430
for the multi-phase transformer 400 of FIG. 4A is disclosed. The
phasor diagram 430 may include a first circle 432 and a second
circle 434, both having a common center S. With respect to the
primary windings and the secondary windings, the phasor diagram 430
is similar to the phasor diagram 130 described above with respect
to transformer 100. For example, a vector of the induced voltage in
the primary windings and the secondary windings are the same. Some
of the differences with respect to the third windings will now be
described.
[0127] Similar to the phasor diagram 130, lines A-AV2, A1V1-A1V2
represent third windings 122A1-122A2, respectively. In transformer
400, a vector of the induced voltage in the third windings is
different than the vector of the induced voltage in the third
windings of transformer 100. The phasor diagram 430 shows an
example of a vector of the induced voltage in the primary windings,
secondary windings and the third windings.
[0128] For example, in one embodiment, for the third winding
coupled to a second winding (example, third winding 122A2), the
vector of the induced voltage in the third winding is substantially
the same as the vector of the induced voltage in one of the primary
windings adjacent the second winding (primary winding 108A).
[0129] In one embodiment, for the third winding coupled to a second
end of a primary winding (example, third winding 122A1 coupled to
primary winding 108A), the vector of the induced voltage in the
third winding is about 180 degrees out of phase with the vector of
the induced voltage in a primary winding (primary winding 108B)
other than the primary winding to which the third winding may be
coupled to.
[0130] In another embodiment, a vector of the induced voltage in
the primary windings and the secondary windings is such that a
phase angle of the output voltage at the second end of the third
winding is different than a phase angle of the output at the second
end of the primary winding or the secondary winding to which the
first end of the third winding may be coupled. For example, the
vector of the induced voltage in secondary winding 116A1 as
depicted by arrow 142 is different than the vector of the induced
voltage in the third winding 122A2, which may be coupled to
secondary winding 116A1, as depicted by the arrow 148.
[0131] In one embodiment, the third windings may be magnetically
coupled no a primary winding such that the phase angle difference
of the output voltage at two adjacent second ends of the third
windings is substantially the same.
[0132] In one embodiment, a vector of the induced voltage in the
primary windings and the secondary windings is such that the phase
angle difference of the output voltage at the two adjacent second
ends of the primary windings and the secondary windings is
substantially the same.
[0133] Another embodiment of a multi-phase transformer
[0134] is described with respect to FIGS. 5A and 5B. Transformer
500 is an example of a nine-phase or eighteen-pulse multi-phase
transformer. The multi-phase transformer 500 described with respect
to FIGS. 5A and 5B is similar to the multi-phase transformer 100
described with respect to FIGS. 1A and 1B.
[0135] One of the differences between transformer 500 and
transformer 100 is that the secondary windings of the second group
of windings include a plurality of sub-windings. Also, the first
end of the secondary windings are coupled to the second end of the
third windings. The description of transformer 500 will be limited
to secondary windings and the third windings. Similarity in the
construction of the transformer 500 with respect to transformer 100
may be understood by referring to FIG. 5A and 5B and description of
transformer 100 provided herein above.
[0136] Referring to FIG. 5A, in this embodiment, the second group
of windings 104 may include a plurality of secondary windings
116A1, 116B1 and 116C1. Each secondary winding, for example,
secondary winding 116A1-116C1 includes a first end 118 and at least
a second end 120. The secondary windings 116A1-116C1 may also
include a plurality of sub-windings connected at a
sub-junction.
[0137] For example, the secondary winding 116A1 may include a first
sub-winding 116A11 and a plurality of second sub-windings 116A12,
116A13, 116A14 and 116A15. One end of the first sub-wincing 116A11,
second sub-winding 116A12 and second sub-winding 116A13 are coupled
together to define a sub-junction 118'. The other end of the first
sub-winding 116A11 corresponds to the first end 118 of secondary
winding 116A1. The other end of the second sub-winding 116A12 may
be coupled to an end of another second sub-winding 116A14 at
sub-junction 120'. The other end of second sub-winding 116A14
corresponds to a second end 120 of secondary winding 116A2. The
other end of the second sub-winding 116A13 may be coupled to an end
of another second sub-winding 116A15 at sub-junction 120''. The
other end of second sub-winding 116A15 corresponds to another
second end 120 of secondary winding 116A2.
[0138] Each secondary winding 116A1-116C1 may be magnetically
coupled to one of the primary windings 108A-108C. In one
embodiment, each of the sub-windings for example, first
sub-windings and second sub-windings may be magnetically coupled to
different primary windings. The first end 118 of each secondary
winding, for example, secondary winding 116A1-116C1 may be coupled
to a second end of a third winding 122A1-122A3. For example, the
first end 118 of secondary winding 116A1 may be coupled to second
end of third winding 122A1.
[0139] The third group of windings 106 may include a plurality of
third windings. For example, plurality of third windings
122A1-122A3, 122B1-122B3 and 122C1-122C3. Each third winding, for
example 122A1-122C3 has a first end 124 and a second end 126. Each
third winding 122A1-122C3 may be magnetically coupled to one of the
primary windings, for example, a primary winding 108A-108C.
[0140] In one embodiment, the first end 124 of some of the third
windings, for example, third winding 122A1 may be coupled to a
primary winding, for example, primary winding 108A. For example,
some of the first end 124 are coupled to one of the second ends
114A-114C. For example, the first end 124 of the third winding
122A1 may be coupled to second end 114A.
[0141] In one embodiment, the first end 124 of some of the third
windings, for example, third windings 122A2-122A3 may be coupled to
a secondary winding, for example, secondary winding 116A1. For
example, some of the first end 124 is coupled to one of the
sub-junctions of a secondary winding. The first end 124 of third
winding 122A2 may be coupled to sub-junction 120' of secondary
winding 116A1. The first end 124 of third winding 122A3 may be
coupled to sub-junction 120'' of secondary winding 116A2.
[0142] In one embodiment, a phase angle difference of the output
voltage Vout1 at two adjacent second ends of third windings is
substantially the same. For example, the phase angle difference of
the output voltage Vout2 at second end 126 of two adjacent third
windings 122A1-122A2 is substantially the same.
[0143] In one embodiment, the output voltage Vout2 at the second
end of the third windings is substantially equal. For example, the
output voltage Vout2 at the second end 126 of the third windings
122A1-122A3, 122B1-122B3 and 122C1-122C3 is substantially the
same.
[0144] In one embodiment, an output voltage Vout1 at the second end
of secondary windings and at the second end of the primary windings
is the same. For example, the output voltage Vout1 at the second
end 120 of secondary windings 116A1, 116B1 and 116C1 and at the
second end 114A-114C of the primary windings 108A-108C is
substantially equal.
[0145] In one embodiment, the output voltage Vout2 is greater than
output voltage Vout1.
[0146] FIG. 5A also shows an example of a number of turns (for
example, N1-N6) for various windings and sub-windings, with some of
the windings or sub-windings having substantially the same number
of turns. For example, primary windings 108A, 108B and 108C each
may have substantially the same number of turns, for example, N1.
Similarly, sub-windings of secondary windings, for example, first
sub-windings 116A11, 116B11 and 116C11 each may have substantially
the same number of turns, for examples, N3. Similarly, third
windings 122A2 and 122A3 each may have substantially the same
number of turns, for example, N5,
[0147] Now referring to FIG. 5B, a phasor diagram 530 for the
multi-phase transformer 500 of FIG. 5A is shown. The phasor diagram
530 may include a first circle 532 and a second circle 534, both
having a common center S. With respect to the primary windings, the
phasor diagram 530 is similar to the phasor diagram 130 described
above with respect to transformer 100. For example, lines SA, SB
and SC represent primary windings 108A, 108B and 108C,
respectively. Some of the differences with respect to the secondary
windings and third windings will now be described.
[0148] Points A1V1-A2V1, B1V1-B2V1 and C1V1-C2V1 represent the
second ends 120 of the secondary windings 116A1, 116B1 and 116C1,
respectively. Similarly points AV2, A1V2, A2V2; BV2, B1V2, B2V2;
and CV2, C1V2 and C2V2 represent the second end 126 of the third
windings 122A1-122A3, 122B1-122B3 and 122C1-122C3, respectively.
Points A', A1' and A2' represent sub-junctions 118', 120' and 120''
of secondary winding 116A, respectively.
[0149] As an example, line AV2-A' represents the first sub-winding
122A11, line A'-A1'' represents the second sub-winding 122A12, line
A'-A2' represents the second sub-winding 122A13, line A1'-A1V1
represents the second sub-winding 122A14 and line A2'-A2V1
represents the second sub-winding 122A15 of secondary winding 116A.
Lines A-AV2, A1'-A1V2, A2'-A2V2 represent third windings
122A1-122A3, respectively.
[0150] As previously discussed, the length of the lines in a phasor
diagram represents the number of turns for the windings. For
example, the length of line S-A represents number of turns N1 for
primary winding 108A. Similarly, the length of line AV2-A'
represents number of turns N3 for first sub-winding 116A11 of
secondary winding 116A1. The length of line A1'-A1V2 represents the
number of turns N5 for third winding 122A2.
[0151] The lines SA, SB and SC represents the input AC voltage Vin
applied to the second ends A, B and C of the primary windings
108A-108C. As it is evident from the phasor diagram, a three phase
input voltage Vin depicted as phaseA_230, phaseB_230 and phaseC_230
is applied, with each phase separated by about 120 degrees.
[0152] As previously described, the lines in a phasor diagrams are
vector lines depicting a vector of the induced voltage. For
example, the vector of the induced voltage in primary windings SA,
SB and SC are depicted by the arrows 536, 533 and 540. Similarly,
one arrows on lines representing the secondary windings and the
third windings represent the vector of the induced voltage. For
example, arrows 542 and 544 represent the vector of the induced
voltage in the sub-windings 116A12 and 116A13 of secondary winding
116A1. The arrows 546 and 548 represent the vector of inducted
voltage in the third winding 122A1 and 122B1.
[0153] In one embodiment, a vector of the induced voltage in the
primary windings and the secondary windings is such that a phase
angle difference of the output voltage at two adjacent second ends
of the primary windings and the secondary windings is substantially
the same. In one embodiment, some of the sub-windings of a
secondary winding may be magnetically coupled to different primary
windings.
[0154] In another embodiment, a vector of the induced voltage in
the third windings is such that the phase angle difference of the
output voltage at two adjacent second ends of the third windings is
substantially the same. The phasor diagram 530 shows an example of
the vector of the induced voltage in the secondary windings and the
third windings.
[0155] Additional embodiments of multi-phase transformers will be
described now. One common feature of these multi-phase transformers
is that in the first group of windings, each of the primary
windings may include a plurality of sub primary windings. The sub
primary windings are coupled in series at an interior junction. One
end of each of the primary windings is coupled together at a common
junction to form a WYE configuration. The other end of the primary
windings defines a second end. Various embodiments of multi-phase
transformers with a plurality of sub primary windings will now be
described.
[0156] FIGS. 6A and 6B show an example of a multi-phase transformer
600, according to one embodiment. Transformer 600 is an example of
a nine-phase or eighteen-pulse multi-phase transformer. Transformer
600 is similar to the multi-phase transformer 100 described above
with respect to FIGS. 1A and 1B in that multi-phase transformer 600
has a primary group of windings 102, secondary group of windings
104 and third group of windings 106. One difference between
transformer 600 and transformer 100 is that the primary windings
include a plurality of sub windings coupled in series.
[0157] Referring to FIG. 6A, in this embodiment, the first group of
windings 102 may include a plurality of primary windings 108A-108C.
One end of the primary windings is coupled together at a common
junction CJ to form a WYE configuration. The second end of each of
the primary windings is configured to receive one phase of a
multi-phase input voltage.
[0158] Each of the primary windings may include a plurality of sub
windings. For example, primary winding 108A may include a plurality
of sub windings 108A1, 108A2 and 108A3. One end of sub winding
108A1 may be coupled to the common junction CJ. Sub windings 108A1
and 108A2 are coupled together in series at interior junction
112A1. Sub windings 108A2 and 108A2 are coupled together in series
at interior junction 112A2. The other end of sub winding 108A3
defines the second end 114A of the primary winding 108A.
[0159] Primary windings 108B and 108C are similarly constructed.
For example, primary winding 108B may include sub primary windings
108B1-108B3 and interior junctions 112B1-112B2. Primary winding
108C may include sub primary windings 108C1-108C3 and interior
junctions 112C1-112C2, respectively.
[0160] The second group of windings 104 may include a plurality of
secondary windings 116A1-116A3, 116B1-116B3 and 116C1-116C3. Each
secondary winding, for example, secondary winding 116A1-116C3 has a
first end 118 and a second end 120.
[0161] Each secondary winding 116A1-116C3 may be magnetically
coupled to one of the primary windings 108A-108C. The first end 118
of some of the secondary windings, for example, secondary winding
116A3 may be coupled to the common junction CJ. The first end 118
of some of the secondary windings may be coupled to an interior
junction of a primary winding. For example, secondary winding 116A1
may be coupled to an interior junction 122A1 of primary winding
108A.
[0162] The third group of windings 106 may include a plurality of
third windings. For example, plurality of third windings
122A1-122A3, 122B1-122B3 and 122C1-122C3. Each third winding, for
example 122A1-122C3 has a first end 124 and a second end 126. Each
third winding 122A1-122C3 may be magnetically coupled to one of the
primary windings, for example, a primary winding 108A-108C.
[0163] In one embodiment, the first end 124 of some of the third
windings may be coupled to a primary winding. For example, the
first end 124 of third winding 122A1 may be coupled to the second
end 114A of primary winding 108A.
[0164] In one embodiment, the first end 124 of some of the third
windings may be coupled to an interior junction of a primary
winding. For example, the first end 124 of third winding 122A2 may
be coupled to interior junction 122A2 of primary winding 108A.
[0165] In one embodiment, a phase angle difference of the output
voltage Vout2 at two adjacent second ends of third windings is
substantially the same. For example, the phase angle difference of
the output voltage Vout1 at second end 126 of two adjacent third
windings 122A1-122A2 is substantially the same.
[0166] In one embodiment, the output voltage Vout2 at the second
end of the third windings is substantially equal. For example, the
output voltage Vout2 at the second end 126 of the third windings
122A1-122A3, 122B1-122B3 and 122C1-122C3 is substantially the
same.
[0167] In one embodiment, the output voltage Vout1 at the second
end of secondary windings and at the second end of the primary
windings is the same. For example, the output voltage Vout1 at the
second end 120 of secondary windings 116A1-116A3, 116B1-116B3 and
116C1-116C3 and at the second end 114A-114C of the primary windings
108A-108C is substantially equal.
[0168] In one embodiment, the output voltage Vout2 is greater than
output voltage Vout1.
[0169] FIG. 6A also shows an example of the number of turns (N1-N8)
for various windings and sub-windings, with some of the windings or
sub-windings having substantially the same number of turns. For
example, sub primary windings 108A1, 108B1 and 108C1 each may have
substantially the same number of turns, for example, N1. Similarly,
secondary windings, for example, secondary windings 116A3, 116B3
and 116C3 each may have substantially the same number of turns, for
example, N7. Similarly, third windings 122A2 and 122A3 each may
have substantially the same number of turns, for example, N6.
[0170] FIG. 6B shows an example of a phasor diagram 630 for the
multi-phase transformer 600 of FIG. 6A. The phasor diagram 630 may
include a first circle 632 and a second circle 634, both having a
common center S. With respect to the primary windings, the phasor
diagram 530 is similar to the phasor diagram 130 described above
with respect to transformer 100. For example, lines SA, SB and SC
represent primary windings 108A, 108B and 108C, respectively. Some
of the differences with respect to the primary windings, secondary
windings and third windings will be described now.
[0171] Points SA1, SA2, SB1, SB2, SC1 and SC2 represent the
interior junctions 112A1, 112A2, 112B1, 112B2, 112C1 and 112C2 of
primary windings, respectively. Line S-SA1 represents the sub
primary winding 108A1.
[0172] Points A1V1-A3V1, B1V1-B3V1 and C1V1-C3V1 represent the
second ends 120 of the secondary windings 116A1-116A3, 116B1-116B3
and 116C1-116C3, respectively. Similarly points AV2, A1V2, A2V2,
A3V2; BV2, B1V2, B2V2, B3V2; and CV2, C1V2, C2V2 and C3V2 represent
the second end 126 of the third windings 122A1-122A4, 122B1-122B4
and 122C1-122C4, respectively. Lines A-AV2, A1V1-A1V2, A2V1-A2V2
and A3V1-A3V2 represent third windings 122A1-122A4,
respectively.
[0173] As previously discussed, a length of a line in a phasor
diagram represents the number of turns for the windings. For
example, the length of line S-SA1 represents number of turns N1 for
sub primary winding 108A1. Similarly, the length of line SA1-A1V1
represents number of turns N5 for secondary winding 116A1. The
length of line SA2-A1V2 represents the number of turns N6 for third
winding 122A2.
[0174] Lines SA, SB and SC represent the input AC voltage Vin
applied to the second ends A, B and C of the primary windings
108A-108C. As it is evident from the phasor diagram, a three phase
input voltage Vin depicted as phaseA_230, phaseB_230 and phaseC_230
is applied, with each phase separated by about 120 degrees.
[0175] As previously described, the lines in a phasor diagrams are
vector lines depicting a vector of the induced voltage. For
example, the vector of the induced voltage in primary windings SA,
SB and SC are depicted by the arrows 636, 638 and 640. Similarly,
the arrows on lines representing the secondary windings and the
third windings represent the vector of the induced voltage. For
example, arrows 642 and 644 represent the vector of the induced
voltage in the secondary windings 116A1 and 116A2, respectively.
The arrows 646 and 648 represent the vector of inducted voltage in
the third winding 122A2 and 122A3, respectively.
[0176] In one embodiment, a vector of the induced voltage in the
primary windings and the secondary windings is such that the phase
angle difference of the output voltage at two adjacent second ends
of the primary windings and the secondary windings is substantially
the same.
[0177] In one embodiment, a vector of the induced voltage in the
third windings is such that the phase angle difference of the
output voltage at two adjacent second ends of the third windings is
substantially the same. The phasor diagram 630 shows an example of
a vector of the Induced voltage in the secondary windings and the
third windings.
[0178] Another embodiment of a multi-phase transformer 700 is now
described with respect to FIGS. 7A and 7B. Transformer 700 is an
example of a twelve-phase or twenty-four pulse multi-phase
transformer. The multi-phase transformer 700 is similar to the
multi-phase transformer 600 described above with respect to FIGS.
6A and 6B. One difference between transformer 700 and transformer
600 is that in transformer 700, the secondary windings include a
plurality of sub windings.
[0179] Referring to FIG. 7A, in this embodiment of transformer 700,
the first group of windings 102 may include a plurality of primary
windings 108A-108C. One end of the primary windings is coupled
together at a common junction CJ to form a WYE configuration. The
second end of each of the primary windings is configured to receive
one phase of a multi-phase input voltage.
[0180] Each of the primary windings includes a plurality of sub
windings. For example, primary winding 108A may include a plurality
of sub windings 108A1 and 108A2. One end of sub winding 108A1 may
be coupled to the common junction CJ. Sub windings 108A1 and 108A2
are coupled together in series at interior junction 112A1. The
other end of sub winding 108A2 defines the second end 114A of the
primary winding 108A.
[0181] Primary windings 108B and 108C are similarly constructed.
For example, primary winding 108B may include sub primary windings
108B1-108B2 and interior junction 112B1. Primary winding 108C may
include sub primary windings 108C1-108C2 and interior junction
112C1.
[0182] The second group of windings 104 may include a plurality of
secondary windings 116A1-116A2, 116B1-116B2 and 116C1-116C2. Each
secondary winding, for example, secondary winding 116A1-116C2 has a
first end 118 and at least one second end 120. For example,
secondary windings 116A1, 116B1 and 116C1 may have two second ends
120.
[0183] The secondary windings 116A1, 116B1 and 116C1 include a
plurality of sub-windings. Secondary winding will now be described
in detail with respect to secondary winding 116A1.
[0184] The secondary winding 116A1 may include a first sub-winding
116A11 and a plurality of second sub-windings 116A12 and 116A13.
One end of the first sub-winding 116A11, second sub-winding 116A12
and second sub-winding 116A13 are coupled together to define a
sub-junction 120'. The other end of first sub-winding 116A11
corresponds to the first end 118 of secondary winding 116A1. The
other end of second sub-winding 116A12 corresponds to a second end
120 of secondary winding 116A1. The other end of second sub-winding
116A13 corresponds to another second end 120 of secondary winding
116A1.
[0185] Each secondary winding 116A1-116C2 may be magnetically
coupled to one of the primary windings 108A-108C. In one
embodiment, sub-windings of a secondary winding may be magnetically
coupled to different primary windings. The first end 118 of some of
the secondary windings, for example, secondary winding 116A2 may be
coupled to the common junction CJ. The first end 118 of some of the
secondary windings may be coupled to the second end of a primary
winding. For example, first end 118 of secondary winding 116A1 may
be coupled to second end 114A1 of primary winding 108A.
[0186] The third group of windings 106 may include a plurality of
third windings. For example, plurality of third windings
122A1-122A4, 122B1-122B4 and 122C1-122C4. Each third winding, for
example 122A1-122C4 has a first end 124 and a second end 126. Each
third winding 122A1-122C4 may be magnetically coupled to one of the
primary windings, for example, a primary winding 108A-108C.
[0187] In one embodiment, the first end 124 of some of the third
windings may be coupled to a primary winding. For example, the
first end 124 of third winding 122A2 may be coupled to interior
junction 112A1 of primary winding 108A.
[0188] In one embodiment, the first end 124 of some of the third
windings may be coupled to a sub-junction of a secondary winding.
For example, the first end 124 of third winding 122A1 may be
coupled to sub-junction 120' of secondary winding 116A1.
[0189] In one embodiment, the first end 124 of some of the third
windings may be coupled to a second end of a secondary winding. For
example, the first end 124 of third winding 122A4 may be coupled to
second end 120 of secondary winding 116A2.
[0190] In one embodiment, a phase angle difference of the output
voltage Vout2 at two adjacent second ends of third windings is
substantially the same. For example, the phase angle difference of
the output voltage Vout2 at second end 126 of two adjacent third
windings 122A1-122A2 is substantially the same.
[0191] In one embodiment, the output voltage Vout2 at the second
end of the third windings is substantially equal. For example, the
output voltage Vout2 at the second end 126 of the third windings
122A1-122A4, 122B1-122B4 and 122C1-122C4 is substantially the
same.
[0192] In one embodiment, the output voltage Vout1 at the second
end of secondary windings and at the second end of the primary
windings is the same. For example, the output voltage Vout1 at the
second end 120 of secondary windings 116A1-116A2, 116B1-116B2 and
116C1-118C2 and at the second end 114A-114C of the primary windings
108A-108C is substantially equal. In one embodiment, the output
voltage Vout2 is greater than output voltage Vout1.
[0193] FIG. 7A also shows an example of a number of turns (for
example, N1-N8) for various windings and sub-windings, with some of
the windings or sub-windings having substantially the same number
of turns. For example, sub primary windings 108A1, 108B1 and 108C1
each may have substantially the same number of turns, for example,
N1. Similarly, secondary windings, for example, secondary windings
116A2, 116B2 and 116C2 each may have substantially the same number
of turns, for example, N7. Similarly, third windings 122A2 and
122A3 each may have substantially the same number of turns, for
example, N5.
[0194] FIG. 7B shows a phasor diagram 730 for the multi-phase
transformer 700. The phasor diagram 730 may include a first circle
732 and a second circle 734, both having a common center S. With
respect to the primary windings, the phasor diagram 730 is similar
to the phasor diagram 630 described with respect to transformer
600. For example, lines SA, SB and SC represent primary windings
108A, 108B and 108C, respectively. Some of the differences with
respect to the primary windings, secondary windings and third
windings will be described now.
[0195] Points SA1, SB1 and SC1 represent the interior junctions
112A1, 112B1 and 112C1 of primary windings 108A-108C, respectively.
For example, line S-SA1 represents the sub primary winding
108A1.
[0196] Points A1V1-A3V1, B1V1-B3V1 and C1V1-C3V1 represent the
second ends 120 of the secondary windings 116A1-116A2, 116B1-116B2
and 116C1-116C2, respectively. Points A', B' and C' represent the
sub-junction 120' of secondary windings 116A1, 116B1 and 116C1,
respectively.
[0197] Similarly points AV2, A1V2, A2V2, A3V2; BV2, B1V2, B2V2,
B3V2; and CV2, C1V2, C2V2 and C3V2 represent the second end 126 of
the third windings 122A1-122A4, 122B1-122B4 and 122C1-122C4
respectively. Lines A'-AV2, SA1-A1V2, SA1-A2V2 and A3V1-A3V2
represent third windings 122A1-122A4 respectively.
[0198] As previously discussed, a length of a line in a phasor
diagram represents the number of turns for the windings. For
example, the length of line S-SA1 represents number of turns N1 for
sub primary winding 108A1. Similarly, the length of line S-A3V1
represents number of turns N7 for secondary winding 116A2. The
length of line SA1-A1V2 represents the number of turns N5 for third
winding 122A2.
[0199] The lines SA, SB and SC represents the input AC voltage Vin
applied to the second ends A, B and C of the primary windings
108A-108C. As it is evident from the phasor diagram, a three phase
input; voltage Vin depicted as phaseA_230, phaseB_230 and
phaseC_230 is applied, with each phase separated by about 120
degrees.
[0200] As previously described, the lines in a phasor diagrams are
vector lines depicting a vector of the induced voltage. For
example, the vector of the induced voltage in primary windings SA,
SB and SC is depicted by the arrows 736, 738 and 740. Similarly,
the arrows on lines representing the secondary windings and the
third windings represent the vector of the induced voltage. For
example, arrows 742 and 744 represent the vector of the induced
voltage in the secondary windings 116A2 and 116B2 respectively. The
arrows 746 and 748 represent the vector of inducted voltage in the
third winding 122A2 and 122A3 respectively.
[0201] In one embodiment, a vector of the induced voltage in the
primary windings and the secondary windings is such that the phase
angle difference of the output voltage at two adjacent second ends
of the primary windings and the secondary windings is substantially
the same.
[0202] In one embodiment, a vector of the induced voltage in the
third windings is such that the phase angle difference of the
output voltage at two adjacent second ends of the third windings is
substantially the same.
[0203] The phasor diagram 730 shows an example of a vector of the
induced voltage in the secondary windings and the third
windings.
[0204] Another embodiment of a multi-phase transformer is now
described with respect to FIGS. 8A and 8B. Transformer 800 is an
example of a twelve-phase or twenty four-pulse multi-phase
transformer. Transformer 800 is similar to the multi-phase
transformer 700 described above with respect to FIGS. 7A and 7E.
One difference between the two transformers is that in transformer
8 00 some of the secondary windings are coupled to an interior
junction of the primary winding.
[0205] Referring to FIG. 8A, the construction of the primary
windings 108A-108C of transformer 800 is similar to the
construction of the primary windings 108A-108C of transformer 700.
Construction of the secondary windings and coupling of secondary
windings and third windings will now be described.
[0206] The second group of windings 104 may include a plurality of
secondary windings 116A1-116A3, 116B1-11633 and 116C1-116C3. Each
secondary winding, for example, secondary winding 116A1-116C2
includes a first end 118 and second end 120.
[0207] The secondary windings 116A1-116A2, 116B1-11632 and
116C1-116C2 include a plurality of sub-windings. Secondary winding
will now be described in detail with respect to secondary winding
116A1.
[0208] The secondary winding 116A1 may include a first sub-winding
116A11 and a second sub-winding 116A12. One end of the first
sub-winding 116A11 and second sub-winding 116A12 are coupled
together to define a sub-junction 120'. The other end of first
sub-winding 116A11 corresponds to the first end 118 of secondary
winding 116A1. The other end of second sub-winding 116A12
corresponds to the second end 120 of secondary winding 116A1.
[0209] Each secondary winding 116A1-116C4 may be magnetically
coupled to one of the primary windings 108A-108C. In one
embodiment, sub-windings of a secondary winding may be magnetically
coupled to different primary windings. The first end 118 of some of
the secondary windings, for example, secondary winding 116A3 may be
coupled to the common junction CJ. The first end 118 of some of the
secondary windings may be coupled to the interior junction of a
primary winding. For example, first end 118 of secondary winding
116A1 may be coupled to interior junction 112A1 of primary winding
108A.
[0210] The third group of windings 106 may include a plurality of
third windings. For example, plurality of third windings
122A1-122A4, 122B1-122B4 and 122C1-122C4. Each third winding, for
example 122A1-122C4 includes a first end 124 and a second end 126.
Each third winding 122A1-122C4 may be magnetically coupled to one
of the primary windings, for example, a primary winding
108A-108C.
[0211] In one embodiment, the first end 124 of some of the third
windings may be coupled to a primary winding. For example, the
first end 124 of third winding 122A1 may be coupled to second end
114A of primary winding 108A.
[0212] In one embodiment, the first end 124 of some of the third
windings may be coupled to a sub-junction of a secondary winding.
For example, the first end 124 of third winding 122A2 may be
coupled to sub-junction 120' of secondary winding 116A1.
[0213] In one embodiment, the first end 124 of some of the third
windings may be coupled to a second end of a secondary winding. For
example, the first end 124 of third winding 122A4 may be coupled to
second end 120 of secondary winding 116A3.
[0214] In one embodiment, a phase angle difference of the output
voltage Vout1 at two adjacent second ends of third windings is
substantially the same. For example, the phase angle difference of
the output voltage Vout2 at second end 126 of two adjacent third
windings 122A1-122A2 is substantially the same.
[0215] In one embodiment, the output voltage Vout2 at the second
end of the third windings is substantially equal. For example, the
output voltage Vout2 at the second end 126 of the third windings
122A1-122A4, 122B1-122B4 and 122C1-122C4 is substantially the
same.
[0216] In one embodiment, the output voltage Vout1 at the second
end of secondary windings and at the second end of the primary
windings is substantially the same. For example, the output voltage
Vout1 at the second end 120 of secondary windings 116A1-116A3,
116B1-116B3 and 116C1-116C3 and at the second end 114A-114C of the
primary windings 108A-108C is substantially equal.
[0217] In one embodiment, the output voltage Vout2 is greater than
output voltage Vout1.
[0218] FIG. 8A also shows an example of a number of turns (N1-N8)
for various windings and sub-windings, with some of the windings or
sub-windings having substantially the same number of turns. For
example, sub primary windings 108A1, 108B1 and 108C1 each may have
substantially the same number of turns, for example, N1. Similarly,
secondary windings, for example, secondary windings 116A3, 116B3
and 116C3 each may have substantially the same number of turns, for
example, N7. Similarly, third windings 122A2 and 122A3 each may
have substantially the same number of turns, for example, N5.
[0219] FIG. 8B shows a phasor diagram 830 for the multi-phase
transformer 800. The phasor diagram 830 may include a first circle
832 and a second circle 834, both having a common center S. With
respect to the primary windings, the phasor diagram 830 is similar
to the phasor diagram 730 described above with respect to
transformer 700. For example, lines SA, SB and SC represent primary
windings 108A, 108B and 108C respectively. Some of the differences
with respect to the secondary windings and third windings will be
described now.
[0220] Points SA1, SB1 and SC1 represent the interior junctions
112A1, 112B1 and 112C1 of primary windings 108A-108C respectively.
Line S-SA1 represents the sub primary winding 108A1.
[0221] Points A1V1-A3V1, B1V1-B3V1 and C1V1-C3V1 represent the
second ends 120 of the secondary windings 116A1-116A3, 116B1-116B3
and 116C1-116C3 respectively. Points A1V1', A2V1', B1V1', B2V1',
C1V1' and C2V1' represent the sub-junction 120' of secondary
windings 116A1, 116A2, 116B1, 116B2, 116C1 and 116C2 respectively.
Similarly points AV2, A1V2, A2V2, A3V2; BV2, B1V2, B2V2, B3V2; and
CV2, C1V2, C2V2 and C3V2 represent the second end 126 of the third
windings 122A1-122A4, 122B1-122B4 and 122C1-122C4 respectively.
Lines A-AV2, A1V1'-A1V2, A2V1'-A2V2 and A3V1-A3V2 represent third
windings 122A1-122A4 respectively.
[0222] As previously discussed, a length of a line in a phasor
diagram represents the number of turns for the windings. For
example, the length of line S-SA1 represents a number of turns N1
for sub primary winding 108A1. Similarly, the length of line S-A3V1
represents number of turns N7 for secondary winding 116A2. The
length of line A3V1-A3V2 represents the number of turns N8 for
third winding 122A4.
[0223] The lines SA, SB and SC represent the input AC voltage Vin
applied to the second ends A, B and C of the primary windings
108A-108C. As it is evident from the phasor diagram, a three phase
input voltage Vin depicted as phaseA_230, phaseB_230 and phaseC_230
is applied, with each phase separated by about 120 degrees.
[0224] As previously described, the lines in a phasor diagrams are
vector lines depicting a vector of the induced voltage. For
example, the vector of the induced voltage in primary windings SA,
SB and SC are depicted by the arrows 836, 838 and 840. Similarly,
the arrows on lines representing the secondary windings and the
third windings represent the vector of the induced voltage. For
example, arrows 842 and 84 4 represent the vector of the induced
voltage in the secondary windings 116A3 and 116B3 respectively. The
arrows 846 and 848 represent the vector of inducted voltage in the
third winding 122A4 and 122B4 respectively.
[0225] In one embodiment, a vector of the induced voltage in the
primary windings and the secondary windings is such that the phase
angle difference of the output voltage at two adjacent second ends
of the primary windings and the secondary windings is substantially
the same.
[0226] In one embodiment, a vector of the induced voltage in the
third windings is such that the phase angle difference of the
output voltage at two adjacent second ends of the third windings is
substantially the same.
[0227] The phasor diagram 830 shows an example of a vector of the
induced voltage in the primary windings, secondary windings and the
third windings.
[0228] Another embodiment of a multi-phase transformer 900 is now
described with respect to FIGS. 9A and 9B. Transformer 900 is yet
another example of a twelve phase or twenty four pulse multi-phase
transformer. The multi-phase transformer 900 is similar to the
multi-phase transformer 800 described above with respect to FIGS.
8A and 8B. One difference being that in transformer 900, the second
sub-windings of some of the secondary windings may be magnetically
coupled to a different primary winding than that shown with respect
to transformer 800.
[0229] Similarity in the construction of the transformer 900 with
respect to transformer 800 may be understood by referring to FIG.
9A and 9B and the description of transformer 800 provided herein
above. For example, points A1V1', A2V1', B1V1', B2V1', C1V1' and
C2V1' represent the sub-junction 120' of secondary windings 116A1,
116A2, 116B1, 116B2, 11601 and 11602 respectively.
[0230] One difference between transformer 900 and transformer 800
will now be described with respect to the phasor diagram 930 as
shown in FIG. 9B. In phasor diagram 930, points A1V1', A2V1',
B1V1', B2V1', C1V1' and C2V1' represent the sub-junction 120' of
secondary windings 116A1, 116A2, 116B1, 116B2, 116C1 and 116C2
respectively. Line A1V1'-A1V1 represents she second sub-winding
116A12.
[0231] As previously described, the lines in a phasor diagrams are
vector lines depicting a vector of the induced voltage and arrows
represent the vector of the induced voltage. As it is evident from
the phasor diagram 930, the arrow 943 on line A1V1'-A1V1 represents
the vector of the induced voltage in the second sub-winding
116A12.
[0232] As the line A1V1'-A1V1 is parallel to line SB, which
represents primary winding 108B, the second sub-winding may be
magnetically coupled to primary winding 108B. Further, as the
direction of the arrow on line SB is the same as the direction of
arrow on line A1V1'-A1V1, the vector of the induced voltage in
second sub-winding 116A12 is in phase with the vector of the
induced voltage in primary winding 108B.
[0233] Now, comparing the vector of the induced voltage in the
second sub-winding 116A2 of transformer 300 as shown in FIG. 8A, it
is evident that the second sub-winding 116A2 of transformer 300 may
be magnetically coupled to a different primary winding, for
example, primary winding 108A, as depicted by line SA. Further, the
vector of the induced voltage in the second sub-winding 116A2 of
transformer 800 is about 180 degrees out of phase with the vector
of the induced voltage in the primary winding 108A.
[0234] In one embodiment, a vector of the induced voltage in the
primary windings and the secondary windings is such that the phase
angle difference of the output voltage at two adjacent second ends
of the primary windings and the secondary windings is substantially
the same.
[0235] In one embodiment, a vector of the induced voltage in the
third windings is such that the phase angle difference of the
output voltage at two adjacent second ends of the third windings is
substantially the same.
[0236] The phasor diagram 930 shows an example of a vector of the
induced voltage in the primary windings, secondary windings and the
third windings.
[0237] Another embodiment of a multi-phase transformer is now
described with respect to FIGS. 10A and 10B. Transformer 1000 is
yet another example of a nine-phase or eighteen-pulse multi-phase
transformer. The multi-phase transformer 1000 is similar to the
multi-phase transformer 800 described above with respect to FIGS.
8A and 8B. One difference being that transformer 1000 does not have
some of the secondary windings coupled to the common junction.
[0238] Similarity in the construction of transformer 1000 with
respect to transformer 800 may be understood by referring to FIG.
10A and 10B and the description of transformer 800 provided above.
Some of the similarities and differences are described below.
[0239] Transformer 1000 includes a plurality of secondary windings
116A1, 116A2, 116B1, 116B2, 11601 and 11602. Unlike transformer
800, transformer 1000 does not have secondary windings 116A3, 116B3
and 11603, first end 118 of which were coupled to the common
junction in transformer 800. In addition, transformer 1000 does not
have third windings 122A4, 122B4 and 12204. Transformer 1000
includes nine second ends of third windings and six second ends of
secondary windings.
[0240] The phasor diagram 1030 of transformer 1000 shown in FIG.
10B is substantially similar to the phasor diagram 830 of
transformer 800. However, as one skilled in the art appreciates,
the phasor diagram 1030 depicts a nine phase or 18 pulse
transformer and the phasor diagram 830 is depicts a twelve phase or
twenty four pulse transformer. Hence, the phase angle difference of
an output voltage at two adjacent second ends of the third windings
of transformer 1000 will be different than transformer 800.
[0241] In one embodiment, a vector of the induced voltage in the
primary windings and the secondary windings is such that the phase
angle difference of the output voltage at two adjacent second ends
of the primary windings and the secondary windings is substantially
the same.
[0242] In one embodiment, a vector of the induced
[0243] voltage in the third windings is such that the phase angle
difference of the output voltage at two adjacent second ends of the
third windings is substantially the same.
[0244] The phasor diagram 1030 shows an example of a vector of the
induced voltage in the primary windings, secondary windings and the
third windings.
[0245] Another embodiment of a multi-phase transformer is described
with respect to FIGS. 11A and 11B. Transformer 1100 is an example
of a fifteen phase or thirty pulse multi-phase transformer. The
multi-phase transformer 1100 is similar to the multi-phase
transformer 1000 described with respect to FIGS. 10A and 10B in
that multi-phase transformer 1000 has a primary group of windings
102, secondary group of windings 104 and third group of windings
106. One difference being that the transformer 1100 may include an
additional sub primary winding in the primary windings, providing
an additional interior junction. Furthermore, in transformer 1100,
additional secondary windings are coupled to additional interior
junctions of the primary windings.
[0246] Similarity in the construction of transformer 1100 with
respect to transformer 1000 may be understood by referring to FIG.
11A and 11B and description of transformer 1000 provided above.
Some of the similarities and differences are described below.
[0247] In transformer 1100, each of the primary windings 108A-108C
includes a plurality of sub windings 108A1-108A3, 108B1-108B3,
108C1-108C3. The sub windings are coupled in series to form
interior junctions. For example, the primary winding 108A includes
interior junctions 112A1, 112A2 and 112A3. Similarly, primary
winding 108B includes interior junctions 112B1-112B3 and primary
winding 108C include interior junctions 112C1-112C3.
[0248] Transformer 1100 includes a plurality of secondary windings
116A1, 116A2, 116A3, 116A4; 116B1, 116B2, 116B3, 116B4; 116C1,
116C2, 116C3 and 116C4. In addition, the transformer 1100 has
additional third windings 122A4, 122A5, 122B4, 122B5, 122C4 and
122C5. So, the transformer 1100 includes fifteen second ends of
third windings and twelve second ends of secondary windings.
[0249] Similar to transformer 1000, the first end of secondary
windings may be coupled to an interior junction of a primary
winding. For example, the first end 118 of secondary winding 116A1
may be coupled to the interior junction 112A2 of primary winding
108A.
[0250] Similar to transformer 1000, the first ends of the third
windings are either coupled to the second end of primary windings
or to a sub-junction of secondary windings. For example, the first
end 124 of third winding 122A1 may be coupled to the second end
114A of primary winding 108A. The first end 124 of third winding
122A2 may be coupled to the sub-junction 120' of secondary winding
116A1.
[0251] The phasor diagram 1130 of transformer 1100 is substantially
similar to the phasor diagram 1030 of transformer 1000. However, as
one skilled in the art appreciates, the phasor diagram 1130 depicts
a fifteen phase or thirty pulse transformer and the phasor diagram
1030 depicts a nine phase or eighteen pulse transformer. Hence, a
phase angle difference of the output voltage at two adjacent second
ends of the third windings of transformer 1100 will be different
than transformer 1000.
[0252] In one embodiment, a vector of the induced voltage in the
primary windings and the secondary windings is such that the phase
angle difference of the output voltage at two adjacent second ends
of the primary windings and the secondary windings is substantially
the same.
[0253] In one embodiment, a vector of the induced voltage in the
third windings is such that the phase angle difference of the
output voltage at two adjacent second ends of the third windings is
substantially the same.
[0254] The phasor diagram 1130 shows an example of a vector of the
induced voltage in the primary windings, secondary windings and the
third windings.
[0255] Another embodiment of a multi-phase transformer is now
described with respect to FIGS. 12A and 12B. Transformer 1200 is an
example of a nine phase or eighteen pulse multi-phase transformer.
The multi-phase transformer 1200 is similar to the multi-phase
transformer 1000 described above with respect to FIGS. 10A and 10B
in that multi-phase transformer 1000 has a primary group of
windings 102, secondary group of windings 104 and third group of
windings 106.
[0256] One difference between transformer 1000 and transformer 1200
is that transformer 1200 may be constructed with primary windings
with or without sub primary windings. In one embodiment, the
secondary windings are coupled to the second ends of the primary
windings.
[0257] Similarity in the construction of the transformer 1200 with
respect to transformer 1000 may be understood by referring to FIG.
12A and 12E and description of transformer 1000 provided above.
Some of the similarities and differences are described below.
[0258] Transformer 1200 may include a plurality of primary windings
108A-108C, with a first end of each primary winding coupled
together to form a common junction and a second end 114A-114C
respectively. Transformer 1200 includes a plurality of secondary
windings 116A1, 116A2; 116B1, 116B2; 116C1 and 116C2. Each of the
plurality of secondary windings includes a first sub-winding and a
plurality of second sub-windings. Secondary winding will now be
described in detail with respect to secondary winding 116A1.
[0259] The secondary winding 116A1 may include a first sub-winding
116A11 and a plurality of second sub-windings 116A12 and 116A13.
One end of the first sub-winding 116A11 and second sub-winding
116A12 are coupled together to define a sub-junction 118'. The
other end of first sub-winding 116A11 corresponds to the first end
118 of secondary winding 116A1. The other end of second sub-winding
116A12 may be coupled to an end of another second sub-winding
116A13 to form a sub-junction 120'. The other end of second
sub-winding 116A13 corresponds to the second end 120 of secondary
winding 116A1.
[0260] Each secondary winding 116A1-116C2 may be magnetically
coupled to one of the primary windings 108A-108C. In one
embodiment, sub-windings of a secondary winding may be magnetically
coupled to different primary windings.
[0261] In one embodiment, the first end 118 of the secondary
windings is coupled to the second end of a primary winding. For
example, first end 118 of secondary winding 116A1 may be coupled to
the second end 114A of primary winding 108A.
[0262] The transformer 1200 includes a plurality of third windings
122A1-122A3; 122B1-122B3; and 122C1-122C3.
[0263] Similar to transformer 1000, the first end of the third
windings is either coupled to the second end of primary windings or
to a sub-junction of secondary windings. For example, the first end
124 of third winding 122A1 may be coupled to the second end 114A of
primary winding 108A. The first end 124 of third winding 122A2 may
be coupled to the sub-junction 120' of secondary winding 116A1.
[0264] The phasor diagram 1230 (FIG. 12B) of transformer 1200 may
be understood based upon the teachings of other phasor diagrams
disclosed herein, for example, phasor diagram 1030 disclosed with
respect to FIG. 10B. Point A1' in phasor diagram 1230 represents
the sub-junction 118' of secondary winding 116A1. Similarly, point
A1V1' represents the sub-junction 120' of secondary winding
116A1.
[0265] However, as one skilled in the art can appreciate, in the
phasor diagram 1230, a vector of the induced voltage in some of the
sub-windings of secondary windings are different than the vector of
the induced voltage shown with respect to phasor diagram 1030. For
example, with respect to the secondary winding 116A1, the first
sub-winding 116A11 is represented by line A-A1', the second
sub-winding 116A12 is represented by line A1'-A1V1' and the second
sub-winding 116A13 is represented by line A1V1'-A1V1. The arrow
1243 on line A-A1', arrow 1244 on line A1'-A1V1' and arrow 1245 on
line A1V1'-A1V1 each represent the vector of the induced voltage in
the first sub-winding 116A11, second sub-winding 116A12 and second
sub-winding 116A13 respectively.
[0266] In one embodiment, a vector of the induced voltage in the
primary windings and the secondary windings is such that the phase
angle difference of the output voltage at two adjacent second ends
of the primary windings and the secondary windings is substantially
the same.
[0267] In one embodiment, a vector of the induced voltage in the
third windings is such that the phase angle difference of the
output voltage at two adjacent second ends of the third windings is
substantially the same.
[0268] The phasor diagram 1230 shows an example of a vector of the
induced voltage in the primary windings, secondary windings and the
third windings.
[0269] Another embodiment of a multi-phase transformer is now
described with respect to FIGS. 13A and 13B. Transformer 1300 is an
example of a twelve phase or twenty four pulse multi-phase
transformer. The multi-phase transformer 1300 is similar to the
multi-phase transformer 500 described above with respect to FIGS.
5A and 5B.
[0270] One of the differences between transformer 500 and
transformer 1300 is that transformer 1300 is constructed with
primary windings with sub primary windings. One of the similarities
is that both transformer 500 and transformer 1300 may have some
secondary windings with more than one second end.
[0271] Similarity in the construction of transformer 1300 with
respect to transformer 500 may be understood by referring to FIGS.
13A and 13B and description of transformer 500 provided herein
above. Some of the similarities and differences are described
below.
[0272] Transformer 1300 may include a plurality of primary windings
108A-108C, with a first end of each primary winding coupled
together to form a common junction and a second end 114A-114C
respectively. Each of the primary windings includes a plurality of
sub primary windings that are coupled in series at one or more
interior junctions. For example, primary winding 108A may include
sub primary windings 108A1 and 108A2, coupled in series at inferior
junction 112A1. Primary windings 108B and 108C are similarly
constructed.
[0273] Transformer 1300 includes a plurality of secondary windings
116A1, 116B1 and 116C1. Each of the plurality of secondary windings
includes a first sub-winding and a plurality of second
sub-windings. Secondary winding will now be described in detail
with respect to secondary winding 116A1.
[0274] The secondary winding 116A1 may include a first sub-winding
116A11 and a plurality of second sub-windings 116A12, 116A13 and
116A14. One end of the first sub-winding 116A11 and second
sub-windings 116A12, 116A12 and 116A13 are coupled together to
define a sub-junction 120'. The other end of first sub-winding
116A11 corresponds to the first end 118 of secondary winding 116A1.
The other end of second sub-windings 116A12, 116A13 and 113A14
correspond to a plurality of second end 120 of secondary winding
116A1.
[0275] Each secondary winding 116A1-116C1 may be magnetically
coupled to one of the primary windings 108A-108C. In one
embodiment, sub-windings of a secondary winding may be magnetically
coupled to different primary windings.
[0276] In one embodiment, the first end 118 of the secondary
windings is coupled to the common junction of primary windings. For
example, the first end 118 of secondary winding 116A1 may be
coupled to the common junction CJ.
[0277] The transformer 1300 includes a plurality of third windings
122A1-122A4; 122B1-122B4; and 122C1-122C4.
[0278] The first end of the third windings is coupled to one of the
second end of a primary winding, interior junction of a primary
winding or to a second end of a secondary winding. For example, the
first end 124 of third winding 122A1 may be coupled to the second
end 114A of primary winding 108A. The first end 124 of third
winding 122A2 may be coupled to the interior junction 112A1 of
primary winding 108A. The first end 124 of third winding 122A4 may
be coupled to the second end 120 of secondary winding 116A1.
[0279] The phasor diagram 1330 (FIG. 13B) of transformer 1300 may
be understood based upon the teachings of other phasor diagrams
disclosed herein, for example, phasor diagram 530 described above
with respect to FIG. 5B. For example, point A1' in phasor diagram
1330 represents the sub-junction 120' of secondary winding
116A1.
[0280] However, as one skilled in the art can appreciate that in
the phasor diagram 1330, the vector of the induced voltage in some
of the sub-windings of secondary windings are different than the
vector of the induced voltage shown with respect to phasor diagram
530. For example, with respect to the secondary winding 116A1, the
first sub-winding 116A11 is represented by line S-A1', the second
sub-winding 116A12 is represented by line A1'-A2V1, the second
sub-winding 116A13 is represented by line A1'-A1V1 and the second
sub-winding 116A14 is represented by line A1'-A3V1. The arrow 1343
on line A1'-A2V1, arrow 1344 on line A1'-A1V1 and arrow 1345 on
line A1'-A3V1 each represent the vector of the induced voltage in
the second sub-winding 116A12, second sub-winding 116A13 and second
sub-winding 116A14 respectively.
[0281] In one embodiment, a vector of the induced voltage in the
primary windings and the secondary windings is such that the phase
angle difference of the output voltage at two adjacent second ends
of the primary windings and the secondary windings is substantially
the same.
[0282] In one embodiment, a vector of the induced voltage in the
third windings is such that the phase angle difference of the
output voltage at two adjacent second ends of the third windings is
substantially the same.
[0283] The phasor diagram 1330 shows an example of a vector of the
induced voltage in the primary windings, secondary windings and the
third windings.
[0284] Another embodiment of a multi-phase transformer is now
described with respect to FIGS. 14A and 14B. Transformer 1400 is an
example of a fifteen phase or thirty pulse multi-phase transformer.
The multi-phase transformer 1400 is similar to the multi-phase
transformer 500 described with respect to FIGS. 5A and 5B.
[0285] One of the differences between transformer 500 and
transformer 1400 is that the transformer 1300 is constructed with
primary windings with sub primary windings. One of the similarities
is that the transformer 500 and transformer 1400 both may nave some
secondary windings with more than one second end.
[0286] Similarity in the construction of the transformer 1400 with
respect to transformer 500 may be understood by referring to FIG.
14A and 14B and description of transformer 500 provided herein
above. Some of the similarities and differences are described
below.
[0287] Transformer 1400 may include a plurality of primary windings
108A-108C, with a first end of each primary winding coupled
together to form a common junction CJ and a second end 114A-114C
respectively. Each of the primary windings may include a plurality
of sub primary windings that are coupled in series at one or more
interior junctions. For example, primary winding 108A may include
sub primary windings 108A1 and 108A2, coupled in series at interior
junction 112A1. Primary windings 108B and 108C are similarly
constructed.
[0288] Transformer 1400 includes a plurality of secondary windings
116A1-116A2, 116B1-116B2, 116C1-116C2. Each of the plurality of
secondary windings includes a first sub-winding and a plurality of
second sub-windings. Secondary winding will now be described in
detail with respect to secondary winding 116A1.
[0289] The secondary winding 116A1 may include a first sub-winding
116A11 and a plurality of second sub-windings 116A12, 116A13,
116A14 and 116A15. One end of the first sub-winding 116A11, second
sub-winding 116A12 and second sub-winding 116A13 are coupled
together to define a sub-junction 118'. The other end of first
sub-winding 116A11 corresponds to the first end 118 of secondary
winding 116A1. The other end of second sub-winding 116A12 may be
coupled to an end of another second sub-winding 116A14 at
sub-junction 120'. The other end of second sub-winding 116A14
corresponds to a second end 120 of secondary winding 116A2. The
other end of second sub-winding 116A13 may be coupled to an end of
another second sub-winding 116A15 at sub-junction 120''. The other
end of second sub-winding 116A15 corresponds to another second end
120 of secondary winding 116A2.
[0290] Each secondary winding 116A1-116C2 may be magnetically
coupled to one of the primary windings 108A-108C. In one
embodiment, sub-windings of a secondary winding may be magnetically
coupled to different primary windings.
[0291] In one embodiment, the first end 118 of the secondary
windings may be coupled to the interior junction of a primary
winding. For example, first end 118 of secondary winding 116A1 may
be coupled to the interior junction 112A1.
[0292] Transformer 1400 includes a plurality of third windings
122A1-122A5; 122B1-122B5; and 122C11-122C5. The first end of the
third windings is coupled to one of the second end of a primary
winding or to a sub-junction of a secondary winding. For example,
the first end 124 of third winding 122A1 may be coupled to the
second end 114A of primary winding 108A. The first end 124 of third
winding 122A2 may be coupled to the sub-junction 120'' of secondary
winding 116A1. The first end 124 of third winding 122A3 may be
coupled to the sub-junction 120' of secondary winding 116A1.
[0293] The phasor diagram 1430 (FIG. 14B) of transformer 1400 may
be understood based upon the teachings of other phasor diagrams
disclosed herein, for example, phasor diagram 530 disclosed with
respect to FIG. 5B. For example, point A1' in phasor diagram 1430
represents the sub-junction 120' of secondary winding 116A1.
Similarly, point A1'' in phasor diagram 1430 represents the
sub-junction 120'' of secondary winding 116A1.
[0294] However, as one skilled in the art can appreciate, in the
phasor diagram 1430, the vector of the induced voltage in some of
the sub-windings of secondary windings is different than the vector
of the induced voltage shown with respect to phasor diagram 530.
For example, with respect to the secondary winding 116A1, the first
sub-winding 116A11 is represented by line SA1-SA1', the second
sub-winding 116A12 is represented by line SA1'-A1', the second
sub-winding 116A13 is represented by line SA1'-A1'', the second
sub-winding 116A14 is represented by line A1'-A2V1 and the second
sub-winding 116A15 is represented by line A1''-A1V1. For example,
the arrow 1443 on line A1''-A1V1 and arrow 1444 on line A1'-A2V1
each represent the vector of the induced voltage in the second
sub-winding 116A15 and second sub-winding 116A14 respectively.
[0295] In one embodiment, a vector of the induced voltage in the
primary windings and the secondary windings is such that the phase
angle difference of the output voltage at two adjacent second ends
of the primary windings and the secondary windings is substantially
the same.
[0296] In one embodiment, a vector of the induced voltage in the
third windings is such that the phase angle difference of the
output voltage at two adjacent second ends of the third windings is
substantially the same.
[0297] The phasor diagram 1430 shows an example of a vector of the
induced voltage in the primary windings, secondary windings and the
third windings.
[0298] Another embodiment of a multi-phase transformer is now
described with respect to FIGS. 15A and 15B. Transformer 1500 is an
example of a nine phase or eighteen pulse multi-phase transformer.
The multi-phase transformer 1500 is similar to the multi-phase
transformer 1000 described above with respect to FIGS. 10A and
10B.
[0299] One of the differences between transformer 1000 and
transformer 1500 is that the transformer 1500 may be constructed
with secondary windings without sub-windings. Another difference is
that some of the third windings in transformer 1000 may include a
plurality of sub-windings and more than one second end.
[0300] Similarity in the construction of the transformer 1500 with
respect to transformer 1000 may be understood by referring to FIG.
15A and 15B and description of transformer 1000 provided herein
above. Some of the similarities and differences are described
below.
[0301] Transformer 1500 may include a plurality of primary windings
108A-108C, with a first end of each primary winding coupled
together to form a common junction CJ and a second end 114A-114C
respectively. Each of the primary windings may include a plurality
of sub primary windings that are coupled in series at one or more
interior junctions. For example, primary winding 108A may include
sub primary windings 108A1 and 108A2, coupled in series at interior
junction 112A1. Primary windings 108B and 108C are similarly
constructed.
[0302] Transformer 1400 includes a plurality of secondary windings
116A1-116A2, 116B1-118B2, 116C1-116C2. Each secondary winding
116A1-116C2 may be magnetically coupled to one of the primary
windings 108A-108C.
[0303] In one embodiment, the first end 118 of the secondary
windings may be coupled to the interior junction of a primary
winding. For example, first end 118 of secondary winding 116A1 may
be coupled to the interior junction 112A1.
[0304] The transformer 1400 includes a plurality of third windings
122A1-122A2; 122B1-122B2; and 122C1-122C2. Third windings may have
a first end 124 and at least one second end 126. Some of the third
windings include a plurality of secondary windings and more than
one second end. For example, third windings 122A2, 122B2 and
122C2.
[0305] Third winding will now be described in detail with respect
to third winding 122A2.
[0306] Third winding 12A2 may include a first sub-winding 122A21
and a plurality of second sub-windings 122A22 and 122A23. One end
of the first sub-winding 122A21, second sub-winding 122A22 and
second sub-winding 122A23 are coupled together to define a
sub-junction 124'. The other end of first sub-winding 122A21
corresponds to the first end 124 of Third winding 122A2. The other
end of second sub-winding 122A22 corresponds to a second end 126 of
secondary winding 122A2. The other end of second sub-winding 122A23
corresponds to another second end 126 of secondary winding
122A2.
[0307] Each Third winding 122A1-122C2 may be magnetically coupled
to one of the primary windings 108A-108C. In one embodiment,
sub-windings of a third winding may be magnetically coupled to
different primary windings.
[0308] In one embodiment, the first end of the third windings is
coupled to one of the second end of a primary winding or to a
second end of another third winding. For example, the first end 124
of third winding 122A1 may be coupled to the second end 114A of
primary winding 108A. The first end 124 of third winding 122A2 may
be coupled to the second end 12 6 of third winding 122A1.
[0309] The phasor diagram 1530 (FIG. 15B) of transformer 1500 may
be understood based upon the teachings of other phasor diagrams
disclosed herein, for example, phasor diagram 1000 described above
with respect to FIG. 10B. For example, point A1V1 in phasor diagram
1530 represents the second end 120 of secondary winding 116A1.
Similarly, point AV2' in phasor diagram 1530 represents the
sub-junction 124' of third winding 122A2.
[0310] However, as one skilled in the art appreciates, in the
phasor diagram 1530, the vector of the induced voltage in some of
the secondary windings and third windings and sub-windings may be
different than the vector of the induced voltage shown with respect
to phasor diagram 1000. For example, the line SA1-S1V1 represents
the secondary winding 116A1 and the arrow 1542 represents the
vector of the induced voltage in the secondary winding 116A1.
Similarly, with respect to the third winding 122A2, the first
sub-winding is represented by line AV2-AV2', the second sub-winding
122A22 is represented by line AV2'-A1V2 and the second sub-winding
116A13 is represented by line AV2'-A2V2. For example, the arrow
1443 on line AV2'-A1V2 and arrow 1544 on line AV2'-A2V2 each
represent the vector of the induced voltage in the second
sub-winding 122A22 and second sub-winding 122A23 of third winding
122A2 respectively.
[0311] In one embodiment, a vector of the induced voltage in the
primary windings and the secondary windings is such that the phase
angle difference of the output voltage at two adjacent second ends
of the primary windings and the secondary windings is substantially
the same.
[0312] In one embodiment, a vector of the induced voltage in the
third windings is such that the phase angle difference of the
output voltage at two adjacent second ends of the third windings is
substantially the same.
[0313] The phasor diagram 1530 shows an example of a vector of the
induced voltage in the primary windings, secondary windings and the
third windings.
[0314] As one skilled in the art appreciates, various embodiments
of multi-phase transformers have been described. Using various
variations of the first group of windings, second group of windings
and third group of windings, multi-phase transformers providing
different number of phases or pulses may be configured.
[0315] The number of turns for windings shown in each of the
winding diagrams is exemplary for the multi-phase transformer
described with respect to that winding diagram. For example, number
of turns N1 described with respect to transformer 100 of FIG. 1A
may not be equal to the number of turns N1 described with respect
to transformer 1500 of FIG. 15A.
[0316] Although exemplary vector of the induced voltage in the
primary windings, secondary windings and third windings have been
shown with respect to various phasor diagrams, as one skilled in
the art appreciates, modifications may be made to magnetic coupling
configurations.
[0317] In one embodiment, with respect to six phase or twelve pulse
transformers, a phase angle difference of the output voltage at two
adjacent second ends of third windings are about 60 degrees. In one
embodiment, a phase angle difference of the output voltage at two
adjacent second ends of the primary windings and the secondary
windings are about 60 degrees.
[0318] In one embodiment, with respect to nine phase or eighteen
pulse transformers, a phase angle difference of the output voltage
at two adjacent second ends of third windings are about 40 degrees.
In one embodiment, a phase angle difference of the output voltage
at two adjacent second ends of the primary windings and the
secondary windings are about 40 degrees.
[0319] In one embodiment, with respect to twelve phase or twenty
four pulse transformers, a phase angle difference of the output
voltage at two adjacent second ends of third windings are about 30
degrees. In one embodiment, a phase angle difference of the output
voltage at two adjacent second ends of the primary windings and the
secondary windings are about 30 degrees.
[0320] In one embodiment, with respect to fifteen phase or thirty
pulse transformers, a phase angle difference of the output voltage
at two adjacent second ends of third windings are about 24 degrees.
In one embodiment, a phase angle difference of the output voltage
at two adjacent second ends of the primary windings and the
secondary windings are about 24 degrees.
[0321] Although the present disclosure has been described with
respect to specific embodiments, these embodiments are illustrative
only and not limiting. Many other applications and embodiments of
the present disclosure will be apparent in light of this disclosure
and the following claims.
* * * * *